Large multinational organizations can have significant value, as NATO and the UN have shown in the past. But once the "regulatory capture" effect happens and the UN becomes a platform for genocidal dictatorships to spew anti-Semitic propaganda, we should discard that organization in favor of something better (even if "better" hypothetically had to be "nothing"). A truly global organization is, as you've explained, probably impossible because the bullies won't participate in a fair organization. But large regional organizations can still have value, as long as we recognize their limits and don't look to them for leadership that they can't adequately provide.