There is artistically no equivalent to Flash ever since it died. Nothing else has allowed someone with artistic skills but no programming skills to create animations and games to the same degree and with the same ease.

I think it depends on whether you see Flash as competing with webvideo or with downloadable executables.

It was terrible from a security POV, but the tooling was superb.

I remember my teenage friends creating things with flash in a way that doesn't happen on the modern web.