It is twofold. one: support in general, and creating a schedule where people watch each other together and greatly boost the likelihood that that stream will be suggested to someone else. Engagement in the chat also greatly boosts the likelihood that new viewers will comment/stay longer.
The other thing is full time streamers live a very specific kind of life that is generally very different from most people. I feel there is value in congregating with other people with the same goals and mindset.
By having a community with schedules/party trains streamers learn about each other and form friendships, and in theory everyone wins. I'm ok with streaming to 0 people and then people watching it later but it's a lot more fun when you have all your friends in the chat with you.
Additionally, certain games (like among us just as an example) are way more fun when you're playing in a voice call with people you know as opposed to random people. Having this sort of community makes a lot of games fun that otherwise wouldn't be. High skill multiplayer games might take months of learning to get good at, but if everyone is new this isn't a problem.
I will think more about what could be done to mitigate the potential issues you mention, but from what I've seen the best way is just to remain small and have a strong focus on community building. Beehaw seems to already have a very compatible culture, although I must admit I am new here.