We are distrupting ecosystems but you cant destroy ecosystems. The most urbanized or polluted place on earth is still an ecosystem. It takes time for an abundance of species to emerge that can take advantage of this ecosystem, but it will emerge. Consider the rock dove, evolved to roost in the very specific environment of a rock cliff. Today, however, ecosystems have changed, cities are more or less giant artificial rock cliffs, and pigeon populations are massive in cities as a result.