During the game we will encounter many detailed questions about Cities Skylines 2 and area planning logic. Many users get confused when they encounter this problem, but after reading this solution, you will find that this problem is really easy to solve.
The current design intention should be: wasteland - low-density housing - build supporting service facilities - gradually increase residents' education and land prices over time - replace low-density with medium-density housing when there is demand for medium-density (cannot build medium-density elsewhere) - Further increase population density and land value - eventually replacing high density.
The same goes for businesses and offices. They will be replaced when the population density increases.
In other words, low-density demand is used to expand the land (in line with reality, gradually developing from suburbs to big cities). The core area must slowly develop from low-density. There is no point in unlimited low-density development.
The key is not to think of low-density as big villas, which are the worst old shabby houses. Medium-density is like tube buildings, and high-density is the real luxury residence.
How about it? Is the solution very simple? In fact, as long as you explore more in the game, you can easily find solutions to the detailed planning logic of each area in "City Skylines 2". If you encounter other problems in the game, please pay more attention to the strategies on this site. Make the game easier for everyone.