There's 3 reasons why they like Youtube:
1. easy-to-use (free, no administration)
2. discoverability, though large channels already have a built-in audience that is self-viral!
3. monetization, typically $1k - $5k/million views/month (eligible above 10,000 subscribers for acceptable content)
The downsides are:
1. "copyrights", which are mostly Youtube takedowns (seldom DMCA)
2. the sporadic nature of payments. You might get $0 next month, or $1000. Very mysterious, so creators rely on Patreon to pay their rent.
3. Occasionally your comments get disabled, related to "copyrights." Then you have to manually re-enable, which is a hassle for hundreds of videos.
Oh, and your account could be deactivated at any time. :)