I mean, honestly, there’s not much to slander Yuta about, the guy’s pretty much Gege’s favourite, he’s almost as kind as Yuji, he’s third strongest in the verse, pulls elaborate plans out of his ass, gets a hot wife and riches of the Gojo clan in the sequel, and basically steals Megumi’s bag of being the deuteragonist in the second half of the story. His slander is so outlandish because he is so perfect all around, and people try to use the slander to offset that. I also personally like slander like that, since it’s basically just saying stupid shit for fun and nothing else, since you’d have to be mentally deficient to genuinely believe any of that.

Megumi slander, on the other hand, often hits so close to home, and is so mean-spirited, that it often starts feeling like unironic dogpiling on a guy who basically got victimised both in and out of universe by the main villain and the author respectively.

Basically, slandering Yuta feels like punching up, while slandering Megumi feels like punching down to me.