I personally tried to build more housing, I tried to buy 5 acres and build 5 homes on them. 5 acres could have easily held 5 large homes with big yards. The city zoning board denied me, saying that that 5-acre plot had been zoned for ONE house and an ADU of no larger than 300 sqft. That was when I realized why housing is so expensive.
In this case, it may not have just been that 5 acres was enough "room" for five houses. It gets into questions of building infrastructure for those houses -- sewers, water rights, etc. One development of 5 houses might not move the needle on that, but it then opens the door to neighbors doing the same thing, which could very much require major investment in infrastructure for the area.
But then there is a corresponding increase in property tax revenues to pay for it, so this should require no approval and just be something that happens. The city pays for the new infrastructure from the taxes paid by the new people using it.