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
Remember when the web looked like this?
Fast loading, accessible, secure, adjusts to any screen size. This might be the perfect site.
Why did we stray from the path of good and mess with JavaScript?
Serious answer: because we wanted interactive sites (ajax it used to be called, iirc), like most online shopping.
Less serious answer: indeed, what do we even need javascript for when we have
marqueeandblinktags?