No. The world population has doubled in my lifetime. While I agree that’s too much, I see much faster scientific, medical and technology progress than ever before. I see more chance to be dreamers and explorers, more chances to build a better society. There’s more art, more freedom, and ever higher quality of life. We have been doing much better with more people.
I don’t know what an ideal number would be, but I expect it’s more than half the current population