In practice these restrictions are big enough that non-competes are pretty rare except for key personnel with trade secrets and that the restrictions are reasonably narrow. I don't think I know anyone who has signed one. Of course it's still not great for those few people, but they're usually doing well enough as is.

EDIT: I did some googling around and almost every resource referencing them talks about C-level executives and senior managers. So that should give you a rough idea of their prevalence.