1) ALL movies are mixed in multi-track studios.
2) ALL movies have 95% of their sound effects added in post = FOLEY ARTISTS
3) Dialogue recorded ON-SET is MOSTLY used only for referencing the looping process. An exception would be a scene in an extremely quiet sound stage.
4) ** since ALL films are mixed in multi-track form, a single boom mic overhead a table of 5 actors would give a SINGLE audio track. Hollywood knows this is USELESS in case one of the actors volume needs to be raised. The solution? The are LOOPED in studio in POST. Period.
You can choose to disbelieve this... that's your right, it's America.
However, if you choose to embrace this STANDARD Hollywood practice, you will find you can achieve similar results on your laptop with a decent multi-track program, a small sound board and a mic. You will find your "movies" SOUNDING as good as we try to make them look.