Having more than one “full-time” job is not unheard of, and its particularly a thing where at least one of them is a precarious and/or poorly paid one.
If you work in a professional TV writing room, you simply don't have another job on the side. It's not an option.
For all those hours writers have demonstrably been worse and worse every decade.
If shows take forever to write now, it's because everything is written by committee.
Regular writers are not pulling the crazy hours that Trey Parker and Matt Stone are. And they put out episodes faster than any other show.
I think all of Hollywood is finally falling over. And it's far past time.