Yeah, while the Flash era was definitely great for animation, that was really more because animation was the only real option for video. Streaming video has largely replaced that, and cheap cameras mean animation is way costlier to do now.

It is a shame that the tooling for animation online doesn't appear to be good. I guess the reality is probably that it's just cheaper and easier to render your animation to video, or release as a game. Game engines are working harder to target browsers as a platform, so the latter option will probably come full circle.