Certainly, some films are meant to be dubbed. International Westerns, for example, of the kind filmed in them thar wide open spaces out yonder near Zaragoza in Spain, have such international casts, that if they weren't dubbed into a target language for a specific country, the dialogue would go:

"Hey, you dirty varmint! I saw you pull them aces out of yer sleeve!"
"Drecksau! Du spinnst wohl, was?!"

 At which point, a voice of reason, Svetlana, the Belle of Murmansk, might interject: "rgin  yt  vdgjni." (Literally, "Your carburator is green, but my duck is very ill"). Here it's a good idea to dub, because even with subtitles it would sound strange to hear everyone speaking a different language. (Maybe that accounts for the wooden acting in so many of those League of Nations horse operas —no one understands what anyone else is really saying!) On the other hand, historical documents, perhaps, should be preserved in the original. The best argument I ever saw against dubbing was a scene from Leni Riefenstahl's  epic Nazi documentary, The Triumph of the Will, in which der Führer was ranting and chanting in an ugly gutteral English —vis ze vorld's vorst Cherman akzent!

For most films, however, many countries avoid subtitles almost entirely and dub. In Italy it is big business. Films are dubbed so well and so consistently in Italy, that it is common for a single dubber to shadow the career of a foreign actor for years. For example, with your back turned to the screen, even if the film is in Italian, you know that Woody Allen is speaking, because his dubber is always Italian comic Oreste Lionello. As noted, however, some dubbers are well known as the voices of more than one actor.  Emilio Cigoli does both John Wayne and Clark Gable, so you may actually have to turn around and look at the screen to find out if you're watching Stagecoach or Gone With the Wind.

It's a sociological study, in itself, exactly why some countries go for dubbing and others for subtitles. In some cases, it might simply be a matter of economics. Putting subtitles on a film is infinitely cheaper than good dubbing, which involves a sound studio, hiring voices for each character and doing take after take in an attempt to get the original inflecions into a voice, and then making sure that the new language synchronizes as well as possible with the lip movements on the screen. Nothing is worse than bad dubbing, where the emotions of the voice don't fit the action, and where the synchronization is so out of whack that half the time the actors look like poor souls on street corners making silent fish-like mouth movements to themselves.

Yet, there are certainly other reasons for choosing whether to dub or subtitle. The first time my Italian wife heard Marlon Brando speak with his own voice, she was disappointed, even saddened, by how "unbeautiful" it was! "He could never have been a successful actor in Italy with that voice," she said. (This reenforces my belief that Italians are simply in love with their own language! —all those trippling and honeyed sounds, with no consonant clusters and potato-like r's. Sigh.)  Indeed, except for comics, Italian actors all seem to have that fine, well-modulated, declamatory speaking voice associated with legitimate theater.

Interestingly, voices of even native-speaking Italian actors may be dubbed. One, the director may simply want another voice for the part, perhaps one which is more in keeping with the character. Two —since in Italy the entire sound track is generally put in after the filming, anyway— maybe the original actor just had another date on dubbing day! Three,  an actor might have an unpleasant speaking voice or noticeable regional accent, one or both of which reasons may be behind the fact that for years, even if you saw Sophia Loren speaking Italian on the screen, that wasn't her voice you were hearing —she was dubbed.

Aesthetics aside, there was surely in Italy one overriding factor for dubbing films when talkies started (the late 1920's): films were an ideal medium for spreading a single standard language throughout a nation still divided linguistically by different dialects. Then, after two decades of good dubbing, Italians were so used to standard Italian in films, that when the wave of post-WW II Italian films  known as "Neo-Realism" came in, with their dialogues recorded live in Sicilian, Neapolitan and Roman dialects, it came as a shock to many Italians to realize that they didn't really understand many of their own countrymen! ('Precisely the point,' said more than one Neo-Realist director.)

Italian dubbing is generally so good, so authentic, that mimics will regularly "do" foreign actors who have characteristic vocal styles —say, John Wayne or Jimmy Stewart. Here, even if you don't understand Italian, you may "get it," anyway, because the mimic is imitating a dubbed version which is uncannily close in timbre and delivery to the original. Indeed, in the case of Greta Garbo, the dubbing was so good that Garbo, upon hearing herself in Italian for the first time, sat down and wrote a fan-letter to her Italian voice, owned by actress Tina Latenzi! And some dubbing, of course, requires the same unusual verbal dexterity as the original voice —witness the tongue-twisting pyrotechnics of Stefano Sibaldi, the Italian voice of Danny Kaye.

Perhaps the strangest sidelight in this whole matter is that dubbed voices can become part and parcel of another culture, evoking allusions and inside jokes just as do the original voices in their own culture. The Italian voices of Stan Laurel and Oliver Hardy are the best example of this. When talkies came in, Laurel and Hardy had already achieved world-wide fame on the basis of their short silent movies. There was such a new demand for them speaking, however, that for a time they actually reshot their scenes hurriedly  in other languages(!), pronouncing their lines from  scripts written in phonetic English. These scenes would then be sent abroad to be spliced into the rest of the film, which had been  remade in the target language using local actors! That soon proved impractical, especially for longer feature films. Consequently, for the Italian market the decision was made to dub the films of Laurel and Hardy in  American studios using Italian-American actors, who, presumably, thought they were speaking standard Italian. Their Italian, however, had been maimed by at least one generation of nasal semi-vowels, unrolled r's and Wrigley's Spearmint.

When the studios in Rome reviewed the first dubbed-in-America Laurel and Hardy film to see what they had, the American English accented voices were so hilarious, that someone came up with the idea of redubbing  everyone else into normal Italian, but leaving Stan and Ollie with accents. There followed a nation-wide contest to find the voices of Laurel and Hardy in Italian. One winner was the now famous Italian comic, Alberto Sordi, whose career started as the voice of Oliver Hardy. His anglicized Italian as 'Ollie' has become so much a part of Italian popular culture that an Italian, today, can do Oliver Hardy by saying, with a broad English language accent, "stupido " (accenting the second, instead of the first, syllable, in imitation of Sordi's version of Oliver Hardy) and have it recognized as instantly as an English-speaker would recognize, "Well, here's another fine mess you've gotten me into!" Indeed, Italian mimics still regularly pay tribute to Laurel and Hardy, imitating the dubbed voices. (The Italian voice of Stan Laurel was Mauro Zambuto, who, after WW II, moved to the United States and became a professor of Electrical Engineering at the New Jersey Institute of Technology!)

So, without taking anything away from the  universal nature of the humor of Laurel and Hardy, it is fair to say that in Italy, much of their popularity was —and still is— due to the spectacularly successful way they are dubbed. There is no Italian comic (not even the great Totò) who, by voice alone, is as recognizable as are Laurel and Hardy in Italian.  The only competition in recognizability might be the Italian voice of Donald Duck! Most of the voices in those cartoons are, indeed, dubbed into relatively normal Italian —except for Donald. He still quacks, but his Italian dubber is none other than  Clarence Nash, the original English voice of Donald Duck for the Disney studious and who dubbed himself into many foreign languages —including Japanese! Apparently, Nash was one of the few persons to have truly mastered the difficult trick of compressing air in the cheek cavity and producing articulate quacks! (Phoneticians call this the "buccal voice". To the rest of us, it's known as 'duckspeak'.)

 Anyway, gotta run. I hear the sultry, breathless tones of Rosetta Calavetta on the tube. Marilyn Monroe, to you.