Attrition rate for saplings is pretty high. So in nature when you see a bunch of trees on a hill there are many more trees that didn't survive. But in a building you don't get to have any attrition; you want all trees to survive.
And city buildings can generate surprisingly strong winds. "The wind loading on a skyscraper is also considerable. In fact, the lateral wind load imposed on super-tall structures is generally the governing factor in the structural design. Wind pressure increases with height, so for very tall buildings, the loads associated with wind are larger than dead or live loads."
And city buildings can generate surprisingly strong winds. "The wind loading on a skyscraper is also considerable. In fact, the lateral wind load imposed on super-tall structures is generally the governing factor in the structural design. Wind pressure increases with height, so for very tall buildings, the loads associated with wind are larger than dead or live loads."
(https://en.wikipedia.org/wiki/Tall_buildings#Design_and_cons...)