This is an exaggeration. Just walk around and check the age of buildings in city centers. We did have Dresden but we also have Paris and London. Their big towers survived the war. The royal palaces more than that.

About trees and forests, there are plenty of wilderness where almost nobody lives and nobody chopped wood for staying warm in winter. Example, those areas in Romania or most of the Alps. It was different inside cities. Even if not every city was bombed to dust, people was really chopping trees. My father told me that it was forbidden (Milan, Italy) but winter is cold.