UN won’t do anything because it is fundamentally designed to enforce the will, and preserve the influence of: primarily the United States, and secondarily the other permanent members of the security council. From an international perspective, it’s a joke.
Don’t give USA all the credit for being the only bad faith actor.
But when Three out of the Five permanent members (vetopower) aren’t practicing democracy and upholding human- and or international rights, well, you see the outcome.
It’s designed to be a platform for cooperation and to settle disputes before they turn into conflicts and wars. But that’s not the wish of the majority of the permanent members anymore, resulting in the current situation. Best not to imagine how the current world would look without the UN. I believe that it does protect the world against worse outcomes.