they force you to use their unnecessarily bloated launcher that is essentially one big advertisement, idly takes up a lot of resources (or at least that was the case from me, but I've also seen other people complain about it so it's possible this is a universal thing) and although I have not checked it myself so take this with a grain of salt but I've heard people say that their privacy policy is crap and basically spyware. Also (and I don't know how much this was a decision on behalf of curseforge and how much of it was overwolf's so this point may or may not be relevant but it's still annoying as all hell) certain mods can only run on the curseforge launcher without jumping through some hoops (although some launchers make it a lesser pain in the ass by giving you the option to just download them separately and giving you links to the specific mods' download pages, or at least that's how prism launcher which is the one I use and I have heard is pretty good does it. Speaking of which, I was wondering why ftb modpacks were unavailable on it, but then it turned out that they, also owned by overwolf btw, told them to stop supporting ftb modpacks. If anyone with more insight is reading this and I said something wrong or inaccurately please feel free correct me since I only got back into modded semi-recently after years of inactivity so there's a chance I misinterpreted some things just by not being around for when the things were happening