We're talking about the same toxicity.
I do agree there is less shitposting, but there's a fair amount of it nonetheless. Many other of those activist posts are toned down here... because I expect their expectations are they are largely preaching to the choir.
But just scrolling through the "toots" (again, at mastodon.social) on the main landing page I get...:
"New Yorkers yelling at nazis is fun.
Proud Boys bloodied and jailed during NYC drag queen story hour protest"
(https://mastodon.world/@StillIRise1963/110051510087068465)
"Nate Silver's brain seems to be broken. The "data guy" is literally citing a Twitter poll as if it's meaningful in a political context.
No wonder ABC News is trying to sell off FiveThirtyEight."
(https://mastodon.social/@mattsheffield/110052597467670093)
"Yet another wealthy #GOP donor turns out to be an accused pedophile, groomer, and sex trafficker. You'd almost think the party's obsessive focus on demonizing drag queens and library books was a crude act of misdirection. #USpolitics https://apnews.com/article/lazzaro-rep"
(https://newsie.social/@stevesilberman/110050892922689946 ... mastodon.social showed this to me while scrolling, but clearly this is an example of federated content)
"The neo-Nazis are creeping around, kids.
Remember, every neo-Nazi/MAGA chud/Jordan Peterson fan is a real person with feelings and gross insecurities who is also a loathsome cnt undeserving of a second of your time or attention unless you are a law enforcement agent working in counter-terrorism. Block immediately, report often.*"
(https://beige.party/@GrimmReality/110051420547135356 again, federation at work).
And the replies are, as far as I could tell while casually browsing, all reinforcing.... none at all trying to moderate the severity or civility of the points being made.
This isn't that different than what I saw I Twitter over the years, except there you saw it from many different sides of various debates. And note that my comments aren't about the issues being discussed: it's chiefly about the way they are discussed: toxically.
So I'm sorry, I don't doubt your intentions and that you really do feel more at home and welcome on Mastodon. But it's not because federation has solved the problem of Twitter-like toxicity: it hasn't, not at all. It's maybe reduced it a bit because the filters for ideology are greater (whether those filters are implemented by administrators refusing users or federating to certain servers or because Mastodon is only attracting people of a certain mindset).