People are focusing too much on a single aspect of streaming: the actual streaming.
There is a lot more that goes into making it a career besides pressing “start streaming”
-Raise awareness on other platforms to drive viewers (YouTube, Twitter, IG, etc)
-Work on relationships with other streamers (cross promote) and publishers
-developing content and examining trends to push more viewership and marketability
If you get good income, then you can outsource some of that, but for most people they are basically trying to promote themselves until they get to a point where it makes financial sense to have an agency handle stuff and said agency wants to represent them.