suspending people for using emotes/fireworks after defeating an opponent is ludicrous

[Karasio]

There's a core difference between those games and ff.
Lets say someone blows up your spiderman skinned body in fortnite. You immediately break contact when the match end, you're are taken to a lobby with no other players, and you're expected to que up for again. In ff you're blowing up someones handcrafted character. You break contact from match and you're put into a social hub with people all around you. If you're tilted maybe you make an off hand comment, now someone else is pissed. Im sure you see where this is going.

FF is a social game at its core and preventing a toxic death spiral in the community is important.

That just comes down to a difference in mental fortitude honestly.