I remember the day I learned that Youtube comes preinstalled on iOS devices -- because the Youtube app somehow (despite never being used, let alone being logged into Google) managed to put a push notification on my home screen -- a push notification for a new upload from a fringe alt-right channel with just a few thousand views. Naturally, every single recommended video on that video was alt-right and far right wing with some Neonazis sprinkled in.
Social media drives antisocial behavior and social division intentionally, because these bring huge numbers of clicks and thus ad money.
Fair enough, according to my Apple ID history I did in fact install it a couple years ago. But the point still stands - the app wasn't used, not connected to any account, yet one day it still pushed extremist content to my home screen.
An app cannot send you push notifications unless you have opened the app and allowed push notifications (or gone in to settings an explicitly enabled them, which seems unlikely). So it is incorrect to say "the app wasn't used". It was obviously used, just maybe not in a long time.
Sorry, I'm not trying to nitpick. But it seems like all you've said so far is "An app which I downloaded and enabled push notifications for sent me a push notification recommending a video I didn't agree with politically". The term "extremist content" can mean basically anything depending on who is speaking.
Social media drives antisocial behavior and social division intentionally, because these bring huge numbers of clicks and thus ad money.