just because the population of the sector at game start sits at ___ (I'm not looking it up) doesn't mean that's all the population that those planets are capable of having -- the planets could have just hit the break-even point that results from their social programs, and not material limitations -- and a newly colonized planet with room for people to stretch their legs that's a mere flight away from every planet in the sector might change that.
What is the point of concocting these convoluted rationalizations for things that don't make sense and aren't good? It may be a fun solipsistic mental exercise but I'm not sure it contributes to a discussion of gameplay that need to be changed.
Sure, the sector
could be on the cusp of some tipping point, and you're playing as the first wave of a renaissance of tonnes of new planets and colonies inhabited by basement-dwelling newlyweds but if so:
1: The narrative needs to firmly establish that's the situation.
2: Other factions and NPCs need to colonize planets, not just the player.
3: If player is going to be as big as other faction, the game has to be a fully 4x game, or it will have no internal consistency at all. It isn't 4x, and it shouldn't be.
Xan is right, the game shouldn't print new people like Zimbabwean dollars. They need to come from somewhere. If 1 planet gains an order of magnitude, another should drop an order of magnitude with stability penalties to each for a while.
The pop growth has to falloff after 10s of millions, or game has to be a 4x game in order to not suck.