@mjg59 I don't know if you are subtooting this, but this threas broadly summarizes my experience:
https://grapheneos.social/@GrapheneOS/116550899908879585
As someone with an infosec background, I am of course highly intrigued by the tech and what it *theoretically* enables. But my experience with big tech so far has been: if a technology is widely deployed and has the potential to strengthen their monopoly, it will be used for that sooner rather than later.
Apple and Google are gradually expanding their use of hardware-based attestation. They're convincing a growing number of services to adopt it. Google's Play Integrity API and Apple's App Attest API are very similar. Apple brought it to the web via Privacy Pass, which Google intends on doing too.
@mjg59 The fixation on this topic may come from the fact that there is no turning back on this one once hardware attestation is baked into everone's personal devices.
I see a lot of advantages if I am the attesting party, instead of being the attested party (i.e. your signal use case vs GrapheneOS's Google/Android issue). But again, Google started by letting users attest their own boot chain and is now continuously switching to a Google-only solution.