>technically speaking, if every household had solar panels and batteries it would not only be cheaper than the grid
Absolutely not, economies of scale. To say nothing of the cost incurred when an issue appears with your installation (lightning strike, water damage, etc) would be much higher.
The problem is that the grid doesn’t really get economies of scale.
Just the grid is often up to 50% of people’s electricity bills, cutting that out is a massive saving.
I think we might see a future where the grid becomes smaller. Still utility scale but skip the continental transmissions and instead run a local city scale grid with renewables, storage and a chemical based carbon neutral backup.