Some of you might remember when a 3mb flash animation could pack in some 5 minutes of animation, with the more advanced ones even having chapter/scene selectors, which could also include clickable easter eggs and other kinds of interactions during the scenes.
Wasn’t it also proprietary, and you needed Adobe software to create it?
Flash animations have a rather specific usecase imho, as your example proves. It’s not a game, it’s not a movie, it’s (usually) more than a simple animated loop.
There’s no exact equivalent for that, but the www has developed way beyond it in all aspects.
At the beginning it was. Later you could write it in code it was oop. Later there was an offshoot called flex that was even more capable.