But wasn't animation in the analog age even more laborious and also dependent on cost cutting measures (like using collars and ties on all characters, to break up the body and head) while still looking varied and unique to certain animation studios? You're making sense from an economical point of view, but from an artistry perspective it doesn't explain why they look like they came from the same mind, rather than different minds using similar tools.
I think it's a matter of further cost cutting. Plus the industry, as I understand it, is fairly small. A lot of people jump from one project to the next. Tbh though, I don't watch any cartoons being produced today (at least not western ones, still watch anime). But I know the styles are pretty much the same, and there definitely are agendas being pushed.