There were other reasons behind the shift to largely steel and concrete construction for multistory buildings in high density areas.
Fire was the main one.
Actually, the first metal frame (iron, IIRC) had a bad problem with quickly collapsing in fires that would not have brought down a timber frame building for a while. The very thick timber beams, girders and columns would char on the outside, but it took some time for the interior wood to burn & loose strength.
However, the iron would crack from thermal stresses or the steel would warp fairly soon. In many cases, current buildings are required by code to have insulation over the metal frame members. What sort of insulation?
Sprayed on wood fiber pulp and clay mix is one method.