I don't know if it was ever really ported to iOS, I've only used it on Android as a mobile platform.
Native plugins were universally bad. Flash was the best of the bunch, but it was still a major issue. Great potential ruined by problematic implementation.
.swf is a fine format, but the software required to display it in a browser was awful. I'm glad it's dead even though I'm sad we lose so much of the old internet now that it's buried.
Ruffle has been doing great for most games and animations, though. It has a similar startup + init + load time Flash player used to have, but without the myriad security vulnerabilities that plagued the web back when native plugins were still a thing.
Of course, Steve Jobs didn't get upset about Flash for any real technical reason. Adobe's CEO didn't entertain his bullshit so Steve threw a hissyfit and kicked Flash off Apple's platform. No technical merits can stand up the arbitrary whims of a billionaire CEO.