Earlier quoted context omitted.
Inquiry: does this apply to other well-paying unions, such as the actors guild and professional sport players? I’m genuinely asking, because as far as I know they are still in existence and regularly ensure better working conditions for their membership without limiting their mobility.
My wife had a client that went on to play in the walking dead. In order for my wife to be able to continue to do her client’s hair, she had to join the actor’s guild and be “licensed” by them and pay dues. So, I’d say they (at least the actors guild) def can reduce your mobility, even say which hair stylists you are and aren’t allowed to use.
It seems a stretch to say the union interfered with her 'mobility', any more than you can't do plumbing on a public building without having a license etc.