> There just aren't good arguments for noncompetes. People often bring up trade secrets, but that's not convincing -- there are already laws against stealing trade secrets, so you don't need noncompetes for that.

Technically yes, but to play devil's advocate: it's easy for someone to provide trade secrets to a new employer without leaving a trail of evidence behind, and it's a lot easier to prove someone worked for a competitor than it is to prove someone gave a competitor trade secrets, so there is a valid argument for why employers might want to enforce non-competes.

Whether that justifies their enforceability or not is a different question.