Over-powered implies that it exists within the game system and functions as a part of it, but is just too strong of general balance - Stealth is not OP, but rather it is completely busted to the point of eliminating the rest of the game system in its entirety. You can't really use stealth and feel like you're legitimately playing the game, at the moment, because it's functionally game-sanctioned cheating in any encounter.
You can't actually play with and use Stealth as a legitimate mechanic in the game, or work that into your play style in encounters and situations where it is appropriate, because it's such a broken system; there is no 'gameplay' to be had, but rather the personal question f "Do I stealth this encounter" where you either do, and the encounter is eliminated with no danger and no risk, and no chance of failure... or you don't, and you play the game without it. If you want to play with an actually functional and meaningful stealth system, you can't.
