That's the "Big Switch" theory. It's one possible future although my sense is that there's considerable skepticism about it from both the perspective of where the economical scale points sit and with respect to governance/control.
You don't chose who provides the electrons coming over your poles in the VAST Majority of locations (some folks run substations to multiple grids, but even then, are talking to the whole other grid, not a single power company).
Deregulated power is about where you send your bill, not who's producing the electrons.
You might keep some temporary capacity / backups locally, but you'll depend on the utility to be there for the vast majority of things.
The market will see if that's the future or not...