The Chrome team says they're not going to pursue Web Integrity but…
it is piloting a new Android WebView Media Integrity API that’s “narrowly scoped, and only targets WebViews embedded in apps.”
They say its because the team "heard your feedback." I'm sure that's true, and I can wildly speculate that all the current anti-trust attention was a factor too.
Proton is made by Steam, which locks you into their platform.
However Wine in general, as well as Lutris also keeps getting better which is great.