For some reason, around the time "digital native" design and designers got big, it suddenly became OK to include giant design-only images (not content, not a logo, not even a fancy button, just because the designer wanted a giant image) in web pages, which before was one of those things you Just Didn't Do in proper web design. It's gotten so bad that now it's done with videos. Web old-timers find this to be in shockingly poor taste, but that's where we are. Bring back the "bad" print-background designers, I say.

Corresponds to a shift from jquery + some manually added plugins to npm / webpack pipelines and using a massive amount of (indirect) dependencies.

You are blithely ignoring the reason for all this bloat: unwanted adtech surveillance.