Exactly, you can even rent seek by buying a plot of land and intentionally keeping the number of units below what demand would suggest. E.g. you have a plot with enough demand to house 20 people but you only build a single family house for 4 people (2 parents 2 children) denying 16 people the possibility to live there. The land is still priced as if it could support 20 people and you make your money off of the sale of the land. This is what people buy into when they buy their house as an "investment". They bank on population growth and increasing demand. If upzoning is impossible then you gain nothing from selling because you have to pay taxes and then buy another property that costs the same amount (which you cant afford because of the taxes), turning the real estate wealth into paper wealth that has to be paid (your mortgage) for but is difficult to draw from except via reverse mortgages.