This contempt is misplaced. It is obviously better in one sense to generate an animation on the fly using a short program instead of encoded its literal pixels in a much larger amount of data even after compression.

The ecosystem has largely moved towards that abstraction because it scales better for virtually every purpose, particularly for rendering in different formats.

Now web developers are brought up inside the abstraction and so don't even think to go outside of it by default. Which would be fine, except that the abstraction isn't designed very well: the browser is massively underpowered at building applications in an foolproof way. Part of that is historical cruft and part of it is (imo) a lack of vision--there should have been a (not-backwards-compatible) replacement for html/js/css years ago which solves its fundamental abstraction problems.

But anyway the present is still much better than the past. You must be nostalgic for the era when all monitors were the same size and websites weren't expected to do anything without reloading the page.