I'm not saying the existing solution is complete, either. But banning noncompetition itself is not the right answer. Why do contract noncompetes clauses exist?

I'm not saying the existing solution is complete, either. But banning noncompetition itself is not the right answer. Why do contract noncompetes clauses exist? What about the small companies and inventors and IP owners? None of these replies I'm seeing have considered the side effects to the world except what would clearly also benefit giant companies.