I think you are severely underestimating what it takes to produce a protein drug like insulin. Getting the bug to make it is just the first step. Then next step is purifying it. Which takes SO much water, and salts, and specialized equipment (resins, columns, high-pressure apparatus). A decentralized insulin production scheme is going to be VERY ecologically destructive.
Buying out a patent and properly documenting it should be doable.
We could revoke the IP and thus force these companies to compete on price... but that hasn't happened. Thus the only solution that is making any progress is circumventing the IP and developing an open process.
There is IP around the production process (specifically the genetic strain of e-coli). Because the production process is biological, generics produced with a different process are not automatically approved by the FDA and have to undergo an expensive approval process. Thus the goal here is to devolop a process with open IP and get that process approved.
You really need to buy out trade secrets of this particular brand.
This is not really decentralized and is really risky, for obvious reason. https://www.ibj.com/articles/eli-lilly-asking-employees-to-w...