What does your tool offer to make sure I never have to deal with abusive users, server patches, or a split-brain scenario?
Split-brain is the "normal mode" of operations for SIT -- it's a decentralized tooling so it expects something to not be available to you until it has been received by you -- at that point it is sitting in its entirety on your computer and you don't need an internet connection.
Abusive users -- depends on a scenario and "gatekeeping" checks -- known/vouched for GPG keys can be used to enforce some policies. Admittedly, this being a new tool, this angle hasn't been worked on extensively (if at all) -- but the way SIT is architectured is to potentially allow for all kinds of scenarios thanks to its flexibility and simplicity.
I'll cut to the chase.
Your answer is basically "You have to do extra work". Which is the wrong answer when trying to replace tools whose major selling is reducing the amount of maintenance work I have to do. This response, unfortunately, commits the basic error of trying to solve a social problem with a technological solution. I don't want to take on the work of guarding the gates. I don't want to guard against potential abuse. I want these things done for me, so I can focus on the parts I care about.
The ability to put in work to monitor abuse and access control in a decentralized manner is not a significant improvement over the ability to do so in a centralized manner.
Oh, and if it interacts with other computers at all then I have to worry about server maintenance. A machine is only truly serverless in isolation. Which would make your tool interesting, but potentially less than maximally useful.
Bluntly, I doubt this will shock the world of software development into being less centralized. The practical benefits of centralization are, apparently, too large to be readily overcome.