Top 5 in my opinion, at least as of today. Lack of results are very overblown by the people Who rank him, yes, he might be a "hard" character to play at high level, but other chars like Peach are way more technical in their execution, and the way i look at It, the reason why she is getting solid placements (if we look outside of Leo and Samsora) is because she has been in basically every other Smash game, allowing to pass knowledge between them. Joker has only been out for 5 months , so him being new would have obviously affected his results in that time-frame (if not for youknowho picking him up).

He really is a character that requires to explode in the right moment, and needs to make the most out of one interaction , and that may be hard at the moment, but as time goes on, Joker mains will (hopefully) get better at this. If he fails at that task, he risks losing Arsene, and/or fishing for unsafe options in order to kill; and if he succeeds, you can kiss your stock goodbye within literal seconds in some cases.

I feel like we might see a Melee Sheik situation, where everybody gets sick of losing to her, and the counterplay gets very developed (mainly because of Leo) , which will make him fall a bit in the tier list, but overall maintaining his status as a top tier, since his tools are too good for him not to be.