This is all accurate, according to an interview that I listened to with a show-runner. Background actors used to be able to survive on their residuals. Now they get paid for one day of work.

Further, the writing staff has been slashed. A show-runner gets a room of writers for a limited time and then they're mostly let go when the season has been written. They don't get to go on set and learn how shows are made to later become producers and show-runners. The interviewee was pretty explicit about how the studios are setting themselves up to have no "new guard" when experienced people retire.

I'm going entirely on things I've heard and read. I am not in the biz. I might be wrong about details. Feel free to correct me.