Considering the various interesting points that was brought up about the P5. I would even question and contradict my own idealism that the P5 should be abolished. Abolishing the position of the P5 is the indeed moral way forward. But we don't live in a perfect world. There were many instances where the UN members states had voted wrongly. Because there were many countries who were already on the side of the Western hegemony, were totally naive, or were just self-interested.
Here are some examples:
1) As
@plawolf had pointed out. Had the PRC been in the P5 since the formation of the UN. Then it could have vetoed the UN resolution to intervene in the Korean War. Instead, that lack of veto power forced the PRC to intervene militarily and that escalated the Korean War. That was one instance where veto power might have stopped a major war that had killed millions.
2) Russia and China had allowed a Western-led UN resolution to impose a no-fly-zone over Libya in 2011 for "humanitarian purposes". It got unanimous UN votes to pass. At the end, Gaddafi was liquidated and Africa was worse off without him in charge of Libya.
3) The West had tabled hostile UN resolutions targeting Syria. Luckily, Russia and China had learnt the lessons of Libya and used their veto powers to block them. Had that not been done, Syria would surely have gone the way of Libya too.
4) During the Ukraine war of 2022. A number of resolutions to condemn Russia got sufficient UN votes to pass and Russia vetoed them. Clearly a good portion of UN member states didn't grasp the true nature of the Russia-Ukraine War.
5) China has vetoed India's ascension into the Nuclear Suppliers Group because India is not a signatory of the nuclear NPT. China was enforcing the true purpose of the NPT. But too many UN member states didn't mind ignoring the NPT for India.
Point is, UN member states have voted wrongly before. And the use of veto power was not always wrong. If the West had wanted to get the UN to pass a mandate for direct military intervention into the Ukraine War, or into a hypothetical Armed Reunification of Taiwan. I'm fairly confident that they could get enough UN member votes to pass. Most of Europe will vote yes. The numerous pathetic vassal states will vote yes. The hostile self-interested neighbouring states would vote yes. If Russia and China cannot veto those resolutions, then it's an escalation into a potential WW3 scenario already.
The UN is a flawed institution, with or without the veto power of the P5. There are no ideal solutions at the end of the day. Majoritarian votes don't always get things right. And the UN members with most military power can always ignore the UN to get what they want. But, no WWIII yet unlike the failed League of Nations.
Remember that in the League of Nations, everyone had veto power. Because of that, many things could not get done, and it was ultimately indecisive. That was the "ideal" solution, yet it had failed to stop WWII from happening. As
@plawolf had pointed out, the most powerful nations won't allow themselves to be governed by lesser nations. If they didn't like the decisions of the League of Nations, they just simply ignored it or just quit. Like Japan, Italy, and Germany. That is the harsh reality of the world.
In the UN, the US won't allow Cuba to pass a UN resolution hostile against itself. Russia won't allow Ukraine to pass a UN resolution hostile against itself. China won't allow the Philippines to pass a UN resolution hostile against itself. If they had no veto powers, then the UN is obligated to enforce those resolutions, thus potentially triggering another world war. Not fair at all, but is it worth a world war to overturn the current status quo of the UN and the P5?