Absolutely NOT the case in the UK TV industry.
Perhaps not today, but certainly in the 50s, when I was awakening form childhood, you had to be close to the movie and tv union. It was very unionised - ACTT, I think. (Neither was it any easier for actors to break into the business.) I got as far as getting a reply to my letter (from David Lean) regarding job prospects in cinematography; teaboy was the gist, but playing teaboy from Scotland was financially impossble unless living on the pavement was an acceptable option. That's nobody's fault but mine for being where I was, not rich, and just one of the games Life plays.
Never mind movies: when I was first designing calendars I ran into problems with getting artwork handled and blocks made. SLADE flexed its muscle and, for a period, you had to get stickers to apply to your artwork in order to permit
blockmakers to handle the stuff. It eventually just went away: those companies needed the work; stuff the union honchos. But it was a difficult period.
Getting a job as an apprentice in a printing works was almost impossible if you didn't come born with ink in your veins, and the latter was as recently as the 80s.
But, that's only one way of looking at it: as a barrier. However, from behind that barrier, it makes damned sound sense and I have a great deal of sympathy.