I have been a 911/police call taker. The pay is mediocre and the stress immense.
The application process will vary a lot based on the jurisdiction you're applying for. I only had to fill out about five pages of paperwork, but I did have to go through a rigorous background check, testing, etc.
Also, this article is wrong. There's no spike in adrenaline when you put the headset on; there's a spike in adrenaline every time a new 911 call comes in.
I'm very grateful that I was on the job before the opioid crisis had reached crisis levels. It's not something I had to deal with. In fact, my first thought based on my experience back then was that it's gotten harder now because you also have to take text messages, which was just starting to be part of the conversation when I was in the job.