The UN Security Council can not act against Russia as they use their veto on any resolution against their invasion. It seems obvious that we need a reformation of the council so no country can block such a resolution one-sided. However, that is not possible as Russia would need to approve that reform, too, which it won't do.
So if we can't reform it, can't we create a new organization similar to the UN? In my imagination, all states could leave the UN, establish "UN 2.0" (leaving Russia as the last and only member of the old UN), and come up with a resolution in that new organization that would legitimate international intervention, alongside a security council without veto permissions.
I know it can't be that easy, but I'm wondering what the blocker would be for this. Is there a reason why this idea is not pursued or discussed?