When I was in law school at UCLA, I considered going into entertainment law. I attended a presentation by a famous entertainment lawyer who said that the lawyers in show business are not actually the most talented — unlike other industries, the big players don't hire primarily from Harvard, Yale, etc.
Instead, the halls of Sony Pictures or Fox are lined with graduates from second- and third-tier law schools who had a foot in the door because of a family connection.
The reason he gave for this is that entertainment law is not as complex as other areas of law, so the basic contract work can be done by a not-stellar lawyer. This was a 15 years ago, and perhaps times have changed. But I'm sure that family/industry connections are still an important part of getting these jobs.
But I do think entertainment lawyers are still very good at what they do. If you look at a popular reference like Mark Litwak's Dealmaking in the Film and Television Industry there's a heavy emphasis on taking the longest possible view because big openings and box office receipts are only tiny part of the overall revenue stream, and the real money is in syndication, foreign sales, merchandise etc. etc.
edit: I heared the above several times over the years, but it appears it may not be true:
https://www.businessinsider.com/sylvester-stallone-on-never-...
IIRC, it was merchandising rights. Sales of the Star Wars action figures were huge, and my understanding kind of unprecedented.
Every professional contract I've ever seen contemplates expansion into future media and markets; it's a technology driven business that has to follow customers to where they are going, and industry lawyers are fully aware that if studios or production companies had the option, most of them would happily relocate to the Moon or Mars to avoid paying out, while maintaining an office on earth to litigate their own copyright interests.