When I log in to Twitter right now I get a message that Ariana Grande has a new album. I don't follow her, I don't care about her, but Twitter decided I needed to see that.
I have notifications disabled but I can only imagine what it pushes out.
On top of that pushing of unsolicited information, the social networks purposely push controversial topics to gain your attention. After a while those controversial and outlandish posts are legitimized and normalized.
How many AOL users were there, total, in the 90s? Now, how many Twitter users are there, today? It's not even a fair fight.
That's only one metric, another would be trust, and clout, and others. The president tweeting is different from a random AOL user posting to a message board. Totally different beasts.
In addition, you have social media boosting other social medias, Facebook, Reddit, this place, each with their own individual brand of shenanigans. You didn't have that way back when (mostly because the alternatives were just as sparse)
Also, I'm not comparing to just the USA twitter users either! It's a global platform. That matters. Retweets are not region-locked!
Global users, of course, Twitter trumps it in count, no doubt. I only assumed US users because the post was about US politics.