Degrowth

It's more about the potential for population growth without needing to leave the solar system or develop FTL space drives or anything super fancy.

These days, people tend to have less children once there is good education and health care. But if things get better and no one needs to have a job, maybe people will return to having more children per person, so it's hard to say how many people there would actually be in the 2300...lots of change will be happening in the meantime.