I doubt Safari will actually die on iOS. The truth is, Safari on iOS is kinda good. That said, honestly this whole line of thinking has gotten pretty tiring. I'm not really sure that an Apple/Google duopoly on browsers is really that much better than the seemingly inevitable Google monopoly. It's not like either of them are particularly good citizens, but Apple's relatively small influence has been very negative in a lot of ways. I'm not even a huge fan of using regulations to solve every problem, but even I must admit that EU regulations have done far more to start to reel in Google than Apple ever could, anyways. As for poor WebM support and pushing wgsl into the WebGPU spec, good riddance.
It's really sad that Google can't be trusted more. There's a lot of people there who are doing good work on Chromium and other web-related projects, and it's besmirched by greedy decisions at worst and optically blind decisions at best. When I was at Google, I did spend a bit of my time trying to make some intranet stuff work better in Firefox... It's probably a token gesture at best, but oh well.
You know we're at a weird point when the underdog competition in browsers is Apple, one of the richest and most resourceful companies of all time.