[patrec]

I don't think what you describe is functionally equivalent. I suspect the main benefit of non-competes is not that you can move around from bigcorp A to bigcorp B (although that's also useful for spreading know-how and utilizing talent efficiently), but rather that ex-employees of bigcorp A form new startups without fear. Would you either fund, found or join a startup if you knew that the threat of a non-compete hangs over you or a founder?