what is the disadvantage of skill based then? i can not think of one.
Probably should have specified slightly better, cause I don't mean skill based like shooters, I mean skill based like skill points and whatever cap it would be.
And I guess it depends on how you look at it, but the major one, imo, is that it can be hard to balance around it. You need to consider the amount of time it takes to go from, say, 1-100, and then how it affects the combat. The problem is most often the player, and open world games would be worse, because you're given the freedom to do what you want, which includes leveling your skills. At some point, you might just level so high that everything is just too easy. If the process is too long, people will just get bored, or feel like they're not accomplishing anything. A good rpg balances gratification and difficulty, you need to feel like you're getting stronger and see how it affects the gameplay, and level based just tends to do that better for my taste. Even a combination of the two, such as Morrowind, is a better option than purely skill based. That might actually be what Cyberpunk does, since I noticed some popups like that.
On the flip side of that, btw, I don't think Oblivion did nearly as well in Morrowind, mostly because they tried to balance it around scaling, which is a terrible way to do it. In that case, you always feel challenged and never like you're getting stronger because everything scales with your progress. Another example might be Titan Quest, which I think had skill based, and the problem there is... well, what if you get bored and want to do something different? You can't really, because you're locked in to how long you used your abilities, which makes choosing something else instead a huge pain. Ultimately though, you can just be good at everything given enough time, and I think that defeats the overall purpose of the game. Being good at everything can be fun, but it can also be extremely boring and limit replayability.
Obviously though this will depend on how you like to play. Some people may like this, and that's cool. Whether you think it's an advantage or disadvantage is really up to the player.