I've heard both Melon Husk and Lil' Jeffy Kisses repeat this sentiment. Where do they even get their figure? Something like 120 billion humans have existed, ever, and there has been only one Einstein and one Mozart. 1/120B * 1T = 8.5.

Factor in the widespread nutritional and medical resource shortages that would come along with one trillion humans, and I'm confident that number would drop to zero.

It seems to be that we'd be better off ensuring the future of humanity and focusing on science. Surely it would be quicker to experiment with genetics to grow an Einstein than it would be to implement a trillion-human breeding lottery hoping to find one.