What people usually mean when they say mankind is destroying the earth is that human action causes a change they don’t like. It sounds odd to say that my wife, by eating a piece of toast for breakfast, is “destroying” the toast. But if I wanted that toast for myself, I might well regard her action as destructive. Same action, but the interpretation depends on purpose and context.
In the economic realm, however, a thing is destroyed to the extent that it loses its usefulness to somebody for doing something. Someone may want to bulldoze my lovely home just for fun. If she pays me enough I may let her do it and be glad she did. When not physically coerced, a trade won’t happen unless each side expects to gain. If it does happen, and if the people who traded are right, then all do in fact gain. Each is better off than before. The trade has created something–value. If they are wrong they destroy value and suffer a loss, which gives them an incentive to avoid making mistakes.
In free markets gains manifest themselves in profit, either monetary or psychi.. People don’t have complete or perfect knowledge and so they make mistakes. They trade when they shouldn’t, or they don’t trade when they should. Fortunately, profits and losses serve as feedback to guide their decisions.
Imperfect though it may be, the free market has so far been the most effective method we know of for doing that.