In the bottom bunk of a bunk bed, there sleeps a grey. (In the top bunk of same there also sleeps a grey but the bottom one is more immediately relevant.)
"It is less than thirteen billion. It has never really felt like not enough."
"I guess maybe eventually we will because we do not stop existing permanently for no reason when we are only forty."
"Yeah, that'll overpopulate you eventually even if everybody only has two."
"I mean fix the space, not say people can't have children. People wouldn't have children if there wasn't space for them."
"Anyway since we don't randomly stop existing for no reason we would not mind waiting until they got us more space."
Snuggle! "So you're pretty low-tech, if glass and the wheel are new. But I guess you have magic doing a lot of the things technology does for us."
"Get us around cities and between countries, let us talk to people far away, let us build really densely so we can fit more people, cure and treat diseases, go to moons, handle data in all kinds of useful ways..."
"Yeah. Some people who didn't want to have kings went down south I think."
"No. Most don't allow immigration because of population problems - the ones that were nice would soon get too full, and then the people who lived there first wouldn't get to have as many kids as they could otherwise. You can switch countries if you find someone who wants to trade with you. In the same caste as you, so the balances of different jobs don't get too off."