I find it very strange that the word "non-compete" does not occur in the article. Having California style non-compete legislation sounds like it would be one of the easiest steps to improve European competitiveness.
This is anecdotal but in my experience in large parts of Europe, this already practically exists.
From what I understand, in Germany at least, companies can demand that employees sign a non compete. However, once an employee departs the company, if the non compete agreement prevents the former employee from finding suitable work, the company must pay your salary until it can either prove that the non compete agreement is not the issue or until it releases the former employees from the agreement. Given those conditions, companies very rarely enforce their noncompete agreements and they’re functionally toothless.
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?