I'll be as straightforward as possible. Ukraine does not have a nuclear deterrent and yet Russia is deterred from using nuclear weapons ergo Ukraine didn't need its own nuclear weapons as a deterrent to prevent Russia from using nuclear weapons. And when even the "despotic regimes" like Russia are refusing to use a weapon, it no longer becomes a credible threat for the ostensibly good guys to threaten to use.

Weapons can only act as a deterrent if your opponent believes you're willing to use them and there are some weapons that no one is willing to use. And if no one is willing to use them, it's probably a waste to develop them in the first place.