Has some scientist suggested how many people is too many for our world?
I don't know many people would trust any scientist who did. After all, if there are too many people who gets to decide which ones are allowed to reproduce and which ones are not? Who decides which people are exterminated to bring populations under whatever level someone says is appropriate?
After the farce of COVID I don't think many people would trust scientists telling us this sort of thing, especially if they were nominated for extermination.