Someone explain Twitch to me

One of the weirdest articles I’ve read in awhile but this:

On top of that, she was $20,000 in debt because her stream setup

What are they using. Are these like sound proofed studio rooms in a home or something? How does a stream setup cost 20k. I feel like the handful of hours in my life that I’ve actually spent looking at any stream seemed really, really basic. Is having a glitchy animated face character really that expensive?