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
I had no problem convincing relatives to use Signal, I am still required to have WhatsApp because every workplace requires it.
Same, but the trick is to force workplace to pay it and deal with it. During the three years I was freelancing I had four company phones at home and had to pay for none of them, other than battery rechargings (and that's when I ever brought them home; on weekends I just powered them off and left them in the garage).
Ah, my workplace requires Telegram, but not WhatsApp. Still lots of people use WhatsApp, so I still have it.