One of my favorite 10 minutes interactions in the @fediforum , was the one with @n00q regarding how he was able to have a working fediverse instance for his friends IRL.
The learning lessons there made me believe there is room for communities-driven instances for home-brewing, HOAs, universities, hobbyists, etc. I know some of these exists, but the kind of guerrilla marketing used in the n00q one was interesting.
I even believe there is a business model to pursue there.