Again: HTML5 was supported way, way before flash disappeared.
https://caniuse.com/?search=canvas
- Basic support in all major browsers since: 2012
- WebGL support in all major browsers since: 2013
- Full support in all major browsers since: 2013 (except Edge, which was released in 2015, IE didn't support everything)
That's way before flash was discontinued. Except of on iOS, but smartphones were never the main platform for flash games/animation.
Flash-style skeletal animation was a result of technical limitations, not a deliberate art choice. The thing that killed flash-style animation was (a) the availability of better things like full-motion rasterized video and (b) the internet moving away from personal websites and towards big platforms, and almost all big platforms restricted the kind of content you can post to text, images and video.