The same goes for privacy. Attestation requires hardware batches be made large enough to provide some privacy protection, and different people seem to interpret the implications of that differently. A couple of people have pointed out, this effectively means you can't revoke a single attestation token without blocking every single person from that hardware batch. It also means that using attestation signals still reveals what batch you're a part of, which is absolutely a fingerprint vector.
There's a lot of conflicting information I see about how this is supposed to be helpful, and I'm constantly wondering if I don't understand it, but I'm also constantly wondering if the push for attestation isn't fueled by a little bit of wishful thinking and willful ignorance of the downsides.
In this very comment section I'm seeing people claim that this could be easily implemented in Linux, but... how? If the point of an attestation token is that it verifies a human is involved in the process, then it kind seems like it defeats the point to have it in an Open Source implementation that any ROM/OS can be built around. Most other systems I've seen that work this way in the wild don't work in community-run codebases; indie browsers don't get to implement EME in a way that lets them stream Netflix shows.
Maybe I'm misunderstanding something, but I've never had attestation explained to me in a way where the claims around what it's capable of and why it can't be abused actually make sense. It feels like a really flawed DRM scheme -- okay, I'll log into a website and the website author will know I'm on an unmodified iOS client from one of X batches of iPhones. That's DRM, how is it not DRM? It's a system for verifying that a local client is unmodified, based on the faulty premise that bots/automation can't be used to send the request from the client.
It's middlemen rolling out DRM (which has always been about control and killing competition and not about piracy) to permanently force themselves into every online transaction or interaction.
With a side benefit of completely eliminating any sort of privacy you might still have.
It's fueled by corporate authoritarianism, nothing more and nothing less.