It means that, from our perspective, there are a lot of people with more money than sense. I agree that it entirely stupid and I would never consider throwing money at a screen this way.
During live streams you can send creators messages. If you pay to send a “special” message the creator will do what the message says. That’s it.
I was reading an article about a streamer who can make 10k a night by streaming her sleeping. She doesn’t do anything other than sleep with the lights on and people give her money.