In the continental US there's three independent grids: East, West, and Texas. There's some interchange of power between the grids with DC ties, but it's pretty minimal capacity-wise.
While a great theoretical model, treating everything as something to be left up to competition is naive and misses the advantages of large coordinated systems.
Such a co-op situation would create the buying power necessary to negotiate good deals. I think this would work for water and internet access too.
The theory is that cities do that for us, but leaders are often compromised by campaign money from the very companies they negotiate with.
Who is going to spend all their time negotiating this, most people are perfectly content paying a little bit more because they didn't have to spend hours arguing with multiple utility providers.
Never mind the increased distribution costs anyways because there's multiple sets of lines running.
The way it works already for most people have the choice of multiple different energy providers with a common grid system, this is what has happened due to the deregulation of the energy space which has been both for better and worse.
But I am talking about individuals joining a co-op that handles it. One that has buying power of many individuals. The co-op would own the last mile, so it not a duplication of the entire network.
With no duplication of the main distribution lines, we are more vulnerable to total outages. It would be better to have some duplication and competition. At least then I can switch. At least then there is an incentive for a utility to be resilient.
As it stands now, PG&E can blows up a neighborhood due to its poor maintenance of gas lines and get a rate increase! And the neighborhood cannot switch away from the utility that killed many of its people.
I live in a condo and we have an HOA that buys many services for all of us. It saves the individual a lot of time and money.
For utilities in California, we have a government body that regulates prices, but its become clear that it is somewhat in bed with the industry, which often happens.
I'd rather have choice than a monopoly regulated by people who are not aligned with the interests of customers.