as you say, a lot of this stuff is already happening. Won’t it be good to have a FOSS attestation stack that breaks the iOS/android duopoly?
Well, it depends. I can now do banking from my desktop computer because there is no way our banks can attest that we're running our browsers in their approved hardware+software stack. Of course they can already disable banking from the browser but if they choose to keep it open but require attestation in your browser when it becomes possible, I don't think it's a good thing.
Unsure what you mean, but for context I use an app developed by a consortium of local banks and it works by scanning a QR code. Indeed, I use an Android phone but my next one will be a de-googled one like a Fairphone with /e/OS. Hopefully the same app will work there...
That's the problem: currently many of those banking apps in the EU require having a phone with Google Play services and other "security" stuff that makes you reliant on American companies, like the post you're replying to claims.