looks like rendering adblockers extensions obsolete with manifest-v3 was not enough so now they try to implement DRM into the browser giving the ability to any website to refuse traffic to you if you don't run a complaint browser ( cough...firefox )
here is an article in hacker news since i'm sure they can explain this to you better than i.
and also some github docs
Exactly. If this comes to pass, you're still free to run an "unattested" browser if you want, but web sites are going to require it "for security" to make sure you are using an "untampered" with browser (I.e. no blocking ads)
I will stop using any websites that try to do that.