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
It's worse than that. Because Chrome is used by nearly everyone and it sometimes takes extra work to get a site compatible with Firefox after it's been developed using Chrome, there are lazy web devs out there trying to drop support for Firefox altogether. Unite everyone under a single monopoly.