I think the concept of micro-grids is the likely direction. The grid itself is too useful to give up, and it's "there". This may be analogous to the co-op that you're suggesting. I think there are already companies that allow you to share your power like that. If I find a link I'll post it.
The grid will become the backup for when there is a local issue with your system, that's my take from a very shallow amount of reading.
Yes! I said a few years ago that we will need decentralization in power grids and mesh networks around the world, not just in software. It will also help prevent a Carrington event and survive an EMP:
The grid is also important to stabilise the frequency of the grid. The inertia of the spinning rotors from the generator helps to counteract the increase in frequency causes by large amounts of export power from the solar inverters
The grid will become the backup for when there is a local issue with your system, that's my take from a very shallow amount of reading.