Oh, that’s definitely revisionism. The iPhone killed Flash, and ActiveX (outside of South Korea / Silverlight) and applets were already dead at that point.
That was the final blow, yup. But the web was still a clunky mess of plugins, broken standards, and browser-specific hacks.
Google pushed to make the web better. And through Chrome they helped bring WebKit to multiplatform: I still remember I couldn't even get rounded edges or nice typography support across platforms, only in Safari.
It wasn’t until Chrome took off that the rest started paying attention.
[1] https://www.engadget.com/2008-10-26-netflix-finally-brings-w... [2] https://netflixtechblog.com/html5-video-at-netflix-721d1f143...
Also the ActiveX security model was pretty horrific.