Actually it was quite simple and more of my fault. I installed UE4.27 to see if that one launches and that one gave me an error right away about not being able to access the Unreal Projects folder. Turns out when uninstalling UE5.0EA a symbolic link got broken (I moved project folder from C drive at one point). So I resolved it fast.
It’s too bad that UE5 doesn’t throw that error, shutting down silently instead.
But, eh, resolved.