The gain from building higher isnt linear. You have to use more space for elevators, re-enforcements, safety(fire for example), etc. The cost of the apartments go up drastically so most people who buy them dont live there, they just invest. Midrises are much better in all of these aspects. Also the materials needed for skyscrapers harder to mamufacture so with all of these they are just plain worse for the environment. Göterborg is a pretty good example of how midrises are better in almost every case.