If you just want something that's free as in price, honestly the best thing (in terms of functionality only) is pirated photoshop natively on windows. I've found PS is kinda crap on Wine.
Photopea is proprietary so at that point you may as well just pirate photoshop, at least then you're getting the real thing.
Dude what the hell??? GIMP has a lot of time in development, also, if you really have a problem with the UI, why don't you report that issue to the Devs instead of whining about it in here?
Why are you being this defensive? I didn't say GIMP was bad, I like it and I use it regularly. I just don't think it's better than Photoshop is all. I'm sure the devs are actively trying to improve the UI too. This seems like a massive overreaction