First of all I hate this "proposals" which is actually, "we implemented this in our flagship product, and kindly force it on our users, you don't have to use it, if you have a choice", stance.
Then comes all the "ensuring they aren't a robot and that the browser hasn't been modified or tampered with in any unapproved ways." part. I'm using an open source browser which is not Chromium based (i.e. Firefox). I can modify and recompile the way I want it. I can use links/elinks/lynx/dillo if I want (and I use them, too). Who do you think you are, and how come dictate my software I use on my own computer?
It's 90s DRM wave all over again. Constant attacks towards open software, open platforms, open protocols.
It's maddening and saddening at the same time.
Except in the 90s you controlled 100% of the code running on your computer. Now there are all kinds of treacherous computing with all those "trusted" execution environments and TPMs and all the other bullshit that can't be avoided, with someone else's public keys burned into the silicon.