Did you like....buy this game and sneak past Powder Gangers and determine sneak is god tier based on that alone?
I don't know what game you're playing (sounds like Skyrim), but I certainly can't sneak directly in front of people unless I have a stealth boy.
The sneak system in a nutshell:
-If it seems like an enemy should be able to spot you, they probably will.
-Any non-silenced firearm will immediately cause caution, if not danger.
-Touching an enemy, even with a stealth boy, means they'll locate you. Typically enemies will start going in the right direction, meaning you have to stay mobile with a stealth boy to avoid detection.
-Stealth boys are highly finite. Good luck spamming them.
If you truly insist sneaking is still broken? Crank the difficulty up. Good luck getting single-shot kills with the stealth weapons, at which point sneaking will really lose it's shine.