There are intentional communities that support themselves with their own, often agriculture based, products sold on the open market. Plus the usual homesteading.

The skills needed for this kind of work are not highly specialized and in general not well paid, therefore levelling the playing field for everyone in the group.

I think the opportunity cost for IT professionals building a SaaS to support the community is a lot higher, and while I would love to see that work, the chances of key community members dropping out to make more money for themselves is fairly high. I'm not sure if a simple time based system for everyone involved is fair, given the high upfront investment to get the skills needed for IT work.