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.
However; courts, Free Software Movement and alternative operating systems plus Mozilla stopped this.
Now all of them are under attack. Esp. Free and Open Software Movement is being enshittified with a process which we can call as "Rewrite it in Permissive Licenses, so companies can hire you while closing down the ecosystem".
We really need a flood to clear this mess.
Sure, there was much closed code, but there was no signed or trusted code. You could still reverse engineer, patch and reflash every single bit of it to your liking, provided you knew what you were doing. On modern hardware, even dumping the decrypted binary for the "trusted execution environment" is a challenge, and getting the thing to run your modified version is simply impossible because it needs to be signed with a key you don't have.