Then their kids will have 4 kids, and you'll need 16x more units with respect to where you started.
Few generations after you have a much deeper problem that the one you started with. Now you live in a country with a population of over 1 billion, where protests cannot be controlled anymore and now you need a totalitarian regime with a massive surveillance and censorship apparatus to keep things under control.
The alternative is that everyone is stressed out and feels the pressure of a system that is over capacity.
Have you heard of Earth day? In 2022, it was April 22. It means that by April 22 we already consumed our environmental budget for the full year.
If we continue like this it's not going to be long until there's mandatory population control.
NOTE: this was edited