difference here being : the crossovers at the top are actually really good and where made with care , audiences liked it and enjoyed it, it also respected each IP it touched properly while the ones at the bottom are mostly crashgrabs that ended up doing nothing interesting with the IPs it brought and the IPs are mostly relegated to "one liners" or "specific quirk" to make people say "there there he said it".

Also a note : In both cathegories there is crossovers that have yet to come out Pibby looks great but I cannot really give fair judgement until it comes out and while I have my doubts about multiversus it cannot be judged until its out.

Personally I judgement of crossovers come down to f the properties crossing over feel like the mesh well or not.

For a broad example Smash Bros. VS Fortnite. I think the crossovers usually work in Smash because the properties at least seem to follow a big rule of them all being originally from video games and not all the characters just feel like they're there to market a brand new game or movie.

With Fortnite the cross over characters and elements are from EVERYWHERE with seemingly the only reason they're being included now is because the property currently popular and marketable or they have a new movie or game coming out.

Example: Avengers movie is releasing soon, shove in Thanos. New Wonder Woman movie is releasing, shove in Wonder Woman. New Uncharted movie is releasing, shove in Uncharted now.

Sadly Playstation all-stars had this problem a bit as well. Why did we get Raiden instead of Snake, New Dante instead of old, and a Bioshock Infinite stage when that game wasn't even out yet ? A ploy to market all the new stuff instead of what would have felt more natural