> but those reasons don't really make sense in a world where patents and trademarks also exist.
Trademarks don’t really help with this. The bigger issue is trade secrets. You can’t make someone forget how your as-yet unreleased prototype is designed, and proving that their subsequent work for a competitor draws on that knowledge is expensive and time consuming. Not to say that non competes are a good idea, just saying trademarks are irrelevant to the conversation, and trade secrets are a more complicated issue than patents.
Trademarks don’t really help with this. The bigger issue is trade secrets. You can’t make someone forget how your as-yet unreleased prototype is designed, and proving that their subsequent work for a competitor draws on that knowledge is expensive and time consuming. Not to say that non competes are a good idea, just saying trademarks are irrelevant to the conversation, and trade secrets are a more complicated issue than patents.