I have an idea for the population growth system.
Namely, that it be replaced with birth rates. (I don't know if this is feasible.)
I imagine it like this.
You can choose like now, with this bar, for example, you invest 50% the difference would be that with the birth rate system now there would be a growth of three children on average, so of 50%.
That would be selectable when growth is completed and starts again, for example every three years, or every 150 rounds.
Anything below a birth rate of 2.00 would then be 10% of your income.
Above that, it would be 2.20 10% 2.40 20%