There are 27,000+ partnered Twitch streamers that probably makes a decent amount of money. But the majority probably can't make a living with streaming alone. The top 0.01% of partners like Shroud or DrDisrespect can make millions.

https://www.twitch.tv/year/2017/factsheet.jpg

The mod team is quite important indeed.

https://streamernews.tv/2015/10/28/guest-writer-moblord-disc...

>How many people make a living from YouTube?

Not many: "96.5% of all of those trying to become YouTubers won't make enough money off of advertising to crack the U.S. poverty line"

http://www.latimes.com/business/la-fi-youtube-stardom-201802...