stealth_nsk
Deity
As far as this general concept goes, I have to say I like it. Hear me out!
It doesn't prevent wide. You don't need districts for a city to be valuable.
You know what I'd like to see? Global Happiness system with unhappiness from districts and buildings instead of cities and population. No crazy formula for calculating district costs, no separate AI to distribute amenities, no 3rd system to limit growth. The same effect, but more clean and simple.