To me twitter started off as like how the facebook timeline used to be, people posted inane stuff about their day. The place for people to overshare. It was the evolution of early 2000s personal blogs now told in a daily stream of single sentence posts.

Then it became celebrity gossip and it continued to be that until celebrities got on and it became the text version of Instagram. As in it was a major advertising portal. Then the scammers/wellness/influencers came in (just like Instagram) and it became where people tried to get people on financial multi level marketing schemes and special pink salt that removes negative ions from your surroundings (that’s still advertising). Around that time Trump was a hot take artist on Twitter and managed to parlay that to the White House (he really worked the media well in 2015/2016 - Twitter was the ultimate guerilla advertising platform then). To that event, whatever good discourse was going on on Twitter was deep in obscurity by like 2012. It had been a culture warzone well before Musk bought it

Everything becoming a punchline, I associate that with twitter. Like no delays joking about sex trafficking and Diddy became a joke day one of his arrest. Joking like that became mainstream on twitter a long time ago