The alternative way to look at it is that early adopters get the volume up such that the price comes down to where more people can afford it?
Solar output is also proportionate to area of sunlight projection. This means the theoretical capacity available to you is proportionate to real estate, area of planetary surface, under your ownership.
This doesn't solve the issue of either storage or continous (and controllable) supply.
Solar panels are already so cheap that household solar is mostly about the installation price.
And more people affording their own panels is still a lot more expensive than fixing the grid.