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
If you have the funds, donate to Mozilla. They're not only the main developers of the only major competing browser engine, but also do a lot of other good work. You can hope for others, but with Firefox only having single-digit usage share it needs all the help it can get.