I don’t think Eugenics or racist is the correct ideas to use here. Less population just means smaller. Not a specific phenotype of human needs to be culled from existance. Just a smaller population.

All biological systems have population limits, and lots of evidence points that humans have passed those limits by quite a bit. Normally, there would be a population collapse due to food scarcity, but humans are capable of pushing those limits with agurcultural science. That doesn’t mean that there are not huge determental effects on the world as a whole for there being an never ending exponential growth of people.