It did because world war 3 hasn’t happened and it’s been about 80 years vs the short time between world war 2 and world war 1.
(VERY importantly, combined with a fundamental agreement on the value of human life, at least to some extent, between the 2 dominant powers Russia and the US and now China)
Not saying that a meeting room where nuclear powers have permanent presence isn't useful. But to say it is responsible for peace somehow is just crazy.