The much maligned "Trusted Computing" idea requires that the party you are supposed to trust deserves to be trusted, and Google is DEFINITELY NOT worthy of being trusted, this is a naked power grab to destroy the open web for Google's ad profits no matter the consequences, this would put heavy surveillance in Google's hands, this would eliminate ad-blocking, this would break any and all accessibility features, this would obliterate any competing platform, this is very much opposed to what the web is.
OTOH, this will create a massive "in" group, and a much smaller "out" group. It almost formalizes the Indie Web, which would take us back to the early 90's, but with better bandwidth. I'd be into that.
Indeed, IDK if you remember back in the bad old days but you used to need a specific browser, and if that browser was IE, good luck if you weren't on Windows. Sites would just block you.
I really hope this doesn't become a thing again - it's already stupid with so many "best on chrome" stuff, but at least I think Apple and Safari put a dent in that because Apple users are a big enough group, and generally identified to have and spend more money than Android / Linux / Windows users so there's that. And Firefox is... well... something. 10% now? IDK, it's hard to be single browser now adays, but with these "for security" things? Who knows.
I guess if Apple, Microsoft and Mozilla all refuse to go this way, it'll break it. The other option is something like Lets Encrypt being big enough they can't delist the attester, but it just attest everything so turns into garbage. Or enough accepted attesters (if it's like SSL PKI) "attest" that you paid them $50 that year and that's about it, so again, everyone who cares gets a Comodo attestation or whatever and use a browser / extension / proxy / OS / whatever that just sends valid garbage or spoofed stuff to them, like many do for the various existing non-secure identity fields.
I've never in my life used IE, and did just fine without it. I've been using Firefox since it was called Netscape, and before that was Mosaic or something. I'm not supporting what Google is trying to do, I'm saying it will have consequences they don't intend. They play whack-a-mole and the moles dig deeper.