users need to be incentivized to do things
Interactions are a natural part of a normal social network.
For example how YouTube incentivizes people to comment?
Or how YouTube comments worth people's time.
There is no money in it, yet people still comment, even on the smallest YouTube channels. And they are often funny.
The "there is no money in it" part can applied to many YouTubers as well. I know YouTubers, who could have partnership and advertisements on their videos, but they are intentionally choose not have those. And they are making quality, entertaining, funny and informative contents.
People use YouTube as it is supposed to be used. As a social network. Without being incentivized.