I agree that it can depend on the show.
For example, shows that undergo a huge time switch between acts 1 and 2, like Sunday in the Park or Grey Gardens. Can you imagine going right from Sunday into...It's Hot in here...or even anything?? Sometimes I agree that those act 1 finales are so...spectactular that the audience needs some time. Or Into the Woods, where the two acts are designed to be incredibly different. And a lot of shows use the intermission to allow some time to pass, perhaps not centuries, but...Wicked goes from Elphaba deciding to defy the wizard to after she has been doing it for months, Les Miz sings about the coming day before the coming day...comes. (yeah, I'm sure I could use better words). Or...could you imaginhe going straight from the end of the Rumble, with the two dead bodies lying on the stage, straight into I Feel Pretty?? That's crazy...(though I suppose you could argue there just wouldn't be a place for I Feel Pretty in that case).
But on the other hand, I can see where sometimes it just stops the action and takes you out of the story. Something like Guys and Dolls, I could see that show going straight from one act to the other, or even Dirty Rotten Scoundrels, as it resumes the exact moment that act 1 leaves off on. At least in these cases, the argument is strictly based on audience, not story, I think.
"If there was a Mount Rushmore for Broadway scores, "West Side Story" would be front and center. It snaps, it crackles it pops! It surges with a roar, its energy and sheer life undiminished by the years" - NYPost reviewer Elisabeth Vincentelli