Another mechanic that I was thinking about is how there could be a special series of buildings for our colonists that can unlock once certain GDP/capita thresholds are met. I believe that this could be the case because certain services require a higher standard of living in a settlement to be sustained, so this could give some more incentive to develop in the most efficient way possible.
For such examples, I was thinking that there could be different tiers of housing that could have other functions as well, such as some housing buildings outputting money, and other potential upgrades could be housing structures having their own Medical, Security, and Entertainment Facilities.
If anyone else has other ideas to contribute here, feel free to discuss them here.