Earlier quoted context omitted.
Even without explicit subsidies, it seems like rooftop solar is still getting hidden subsidies? If homeowners were paid wholesale rates for the power they provide, with prices based on the spot market, would any of it make sense financially?
No, it wouldn't. For the same reason that me operating a coal power plant in my backyard wouldn't provide me with cheaper electricity then just buying from the grid. A centralized utility, even a poorly run one, will always provide electricity safer, cheaper, and more consistently then thousands of tiny private installations.
I will stipulate that PG&E qualifies as a 'poorly run, centralized utility' and based on its billing it cannot provide power to residential homes for less money than a locally installed solar system can.
The reasons for this are worth considering.
PG&E has to maintain a power transmission infrastructure. That infrastructure has a high inspection cost, land use cost, equipment costs, and insurance risk cost (witness that the threat of the being found liable that their transmission line maintenance (or lack thereof) contributed to the most expensive wild fire in CA history).
Then there are the externalities which we don't account for as much in either scenario. Whether it is the cost of scrubbers on a coal plant, the waste storage costs of nuclear, or the gas pipeline infrastructure for natural gas plants that leaks methane into the air.
What solar does it centralizes the manufacture of the energy production equipment with finite externalitie. It provides highly granular capacity that can be deployed without large step wise changes in capacity (this is the 'nearly unused plant' problem where you have to run a plant because the instantaneous need occasionally exceeds your current generate capacity while the average need is staying below that level (this is where Teslas battery farms help energy companies cut costs).
So when comparing systems dollars to systems dollars, Solar with the current economics of about $3.25/watt installed is actually cheaper than poorly run centralized power plants.