Honestly, I don’t think the vetoes are the main issue. In international diplomacy/law, enforceability rules discussions. If all the small countries vote to prevent the US-Iran war and intervene against the US, good luck enforcing it. The vetoes just reflect this reality.

The UN helps coordinate where there is a will to cooperate, but it can’t govern the world, whether veto power exists or not. What could be done to improve this I am not sure, but it is not as simple as removing the veto.