Scenario A: Every actor, sports star, celebrity, singer, entertainer, etc. mysteriously vanish off the face of the earth overnight. Civilization largely continues on with, at most, a few highly localized areas of decline where the economy of that area was built entirely on such things.
Humans have had actors, singers, and performers for a very long time. Art and drama are more fundamental to who we are than medicine, architecture, or chemistry. If every professional performer disappeared tomorrow, you would still tell stories to your friends, you would still whistle tunelessly, and we would all continue to think you suck at it, desperately wishing for someone with a better sense of timing, rhythm, or tune. The Dark Ages were more a failure of Art than of Science.
Scenario B: Every engineer, software developer, scientist, teacher, doctor, etc. mysteriously vanish off the face of the earth overnight. Civilization decays rapidly into a new dark age as all research instantly grounds to a halt, infrastructure gradually rots away, disease and famine become rampant, and, at a minimum, decades of ruin pass before enough of what's left of humanity has relearned enough of the lost knowledge to start climbing back to a state approaching the world we know today.
It's a lot easier to train someone to be a competent physician or engineer than to train them to be a world class actor/artist. Curiously, it also takes a lot more technical people to do anything useful than it does actors to entertain. GM uses 219,000 people to build 8.5 million cars/year. 38 cars per person: individually, those people are not very useful. Monday Night Football is 20 million people watching 92 players and associated, mostly fungible support personnel. Sure, the car has more value than one football game, but that value is very diffuse. There are tons of entertainers in local/regional theater groups, local bands, and local artists who get paid so little that they have to keep day jobs.
Stop comparing elite artists to average technical workers, and you'll find much less discrepancy. The average programmer gets paid much better than the average guitarist.