I did a hard reinstall (uninstall on steam and delete the stuff on your documents > paradox interactive folder as well) and that worked. Ordinarily I wouldn't mention this on the thread itself, but I do have a theory, the launcher wasn't really cooperating even after the reinstall very well, it did load and stuff, but needed to be started several times. That is until I noticed that one of the mods I had but stopped using had actually had its page deleted by the author, so the game was constantly stuck trying to download that file. That wasn't a problem because the game let me start without it if the playset didn't have it in, but when I realised that the descriptor for that mod also didn't exist, the launcher must've been trying to find the descriptor for it but couldn't, so I unsubscribed from that mod and now it only takes a fraction of a second to get the mods loaded.
I think if you guys have any mods that you don't use anymore, check if they still exist in the workshop, or even if you do use them anyway I suppose. Thought that might be of some help. I remember from my modding days that the game REALLY hates not having 100% accurate mod descriptors.