Android shouldn't be considered Open Source anymore, since source code is published in batches and only part of the system is open, with more and more apps going behind the Google ecosystem itself.
Maybe it's time for a third large phone OS, whether it comes from China getting fed up with the US and Google's shenanigans (Huawei has HarmonyOS but it's not open) or some "GNU/Linux" touch version that has a serious ecosystem. Especially when more and more apps and services are "mobile-first" or "mobile-only" like banking.
Allowing apps to say "we only run on Google's officially certified unmodified Android devices" and tightly restricting which devices are certified is the part that makes changes like this deeply problematic. Without that, non-Google Android versions are on a fair playing field; if you don't like their rules, you can install Graphene or other alternatives with no downside. With Play Integrity & attestation though you're always living with the risk of being cut off from some essential app (like your bank) that suddenly becomes "Google-Android-Only".
If Play Integrity went away, I'd be much more OK with Google adding restrictions like this - opt in if you like, use alternatives if you don't, and let's see what the market actually wants.
There are a lot of scams targeting vulnerable people and these days attacking the phone is a very "easy" way of doing this.
Now perhaps there is a more forgiving way of implementing it though. So your phone can switch between trusted and "open" mode. But realistically I don't think the demand is big enough for that to actually matter.
Even with play integrity, you should not trust the client. Devices can still be compromised, there are still phony bank apps, there are still keyloggers, etc.
With the Web, things like banks are sort of forced to design apps that do not rely on client trust. With something like play integrity, they might not be. That's a big problem.
Play integrity hugely reduces brute force and compromised device attacks. Yes, it does not eliminate either, but security is a game of statistics because there is rarely a verifiably perfect solution in complex systems.
For most large public apps, the vast majority of signin attempts are malicious. And the vast majority of successful attacks come from non-attested platforms like desktop web. Attestation is a valuable tool here.
What could possibly go wrong. It's not only morally questionable no matter what "advantages" it provides Google, but it's also technically ridiculous because _even if every single computing device was attested_, by construction I can still trivially find ways to use them to "brute force" Google logins. The technical "advantage" of attestation immediately drops to 0 once it is actually enforced (this is were the seatbelts analogy falls apart).
Next thing I suggest after forcing remote attestation on all devices is tying these device IDs to government-issued personal ID. Let's see how that goes over. And then for the government to send the killing squad once one of these devices is used to attack Google services. That should also improve security.
Here's the dystopian future we're building, folks. Take it or leave it. After all, it statistically improves security!
Yes, for SOME subset of attackers (car crashes), for SOME subset of targets (passengers), the mitigations don’t solve the problem.
This is not the anti-attestation / anti-seatbelt argument many think it is.
All security is mitigation. There is non perfection.
But it makes no sense to say that because a highly motivated attacker with a lot of money to spend can rig real attested devices to be malicious, there must be no benefit to a billion or so legit client devices being attested.
I think your enthusiasm for melodrama and snark may be clouding your judgment of the actual topic.