Google certifies devices unpatched for the last 10 years, rooted, riddled with the malware, because the keys have leaked.
Google knows and still sells the lie.
But you should know better. Google is not selling the actual security, it's just protecting its business.
There is also the problem that most external hardware is less secure than things like Apple's SEP. (But on the other hand, probably more secure than the long tail of cheap Android phones, which use virtualization rather than real hardware.)
That's how it works in Germany: You tap your national ID card (as a citizen) or eID card (as a non-citizen) on any NFC-capable iPhone or Android device. I personally much prefer that solution over one that requires a specifically trusted device.
The big gap is trusted user confirmation, though: Users need to see what they sign by tapping their card, and then you're usually back to some form of attestation.
Practically, they also completely botched the rollout; literally everyone I know managed to somehow lock themselves out of their card at the first attempted use (assuming they've even bothered to set it up).
To me, it seems like just the right amount of friction, and user expectations can work in favor of privacy here: People will hopefully refuse to tap their ID on their phone for a service where they want to remain completely anonymous, even if the protocol technically might support anonymous assertions.