Surely capitalism, and more specifically demand, is the reason? If the current companies paying them millions of dollars per gig say "sorry, we decided we don't

Surely capitalism, and more specifically demand, is the reason? If the current companies paying them millions of dollars per gig say "sorry, we decided we don't like ads and don't want to charge our viewers more, so forget the millions we've now got a $200k offer for your next TV series season Mr Famous Actor" they'll take a job with the first company that once again offers them millions.