It's tough getting into details without spoiling some of the aspects of the show, but yeah there are definitely problematic elements. The character designs are overly sexualized for being middle school girls (case in point, Mami). A key subtextual theme is about how society exploits the images/bodies/persons of young women for cynical profiteering, but the show itself literally also does that as well. There are definitely parts of the show that feel edgy for edginess's sake, although it's probably not the most egregious anime in that respect.

To be honest, I've watched the show a couple times as well as listening to a whole (100% femme cast) recap podcast on the show, and I still have mixed feelings about it. I think it's certainly an influential show, and one that's worthy of critical discussion, but idk if you would have a good time watching it.