My only fear with something like that would be that it would lead to a world full of really invasive tracking while cutting out any devices that didn't have attestation or were running any sort of proxy. Not that I think it's impossible things could be done right, but it being possible and actually expecting tech companies to do it right are two different things.

At least no matter whether I'm behind a proxy or my device has attestation or not I can prove I know what a traffic light is or run some proof of work equation. Not that they aren't annoying though.