nostr:npub1kpwlxpzkxfmuxjmzc2wp3rf9vjg0sgydmlhsnrgqr3maf59h86qqdxxzz4 nostr:npub1nqzzvvr02rm8eqqamu6u403a584ljdtuh0uwdqzdl5maxjn880nss7838y 
I think it was already here before, but it got a significant boom when smartphones became a thing & we got instant access to anything & everything.
As for the rest...
The world is becoming more extremist in its views. Ppl are being pushed further & further apart, to the point where we almost sound alien to one another.
That happened slowly with major help from social media & the ease with which it groups us with similar thinking ppl while separating us from everyone else.