How would you install $6B overnight? That alone would take years. And where do you buy it from? China?
The challenge with large installs is the interconnection queue and permitting, not any industrial capacity limitation. And these could be solved by CPUC with a snap of their fingers, like they snapped their fingers to extend Diablo Canyon.
The ISO (in this case CAISO) runs those studies for a reason to maintain grid reliability. The reason they're slow is that it involves a crazy amount of simulations to determine grid upgrades and it is difficult when things must be done recursively and when the renewables developers speculate so much.
If the state regulator could snap their fingers, they would have done so in California, New York, the Midwest... everywhere. They made some changes to speed things up in Texas, but honestly they're kicking the can down the road.
Solar is down to around 0.25 / watt at bulk. Battery, LiFePo4 is $200/kWh.
Those are retail bulk prices. Commercial/Industrial prices are similar or sometimes better on commercial-sized equipment.
Granted, as you noted interconnection and permitting costs are high and going up and labor costs have risen and those are the main costs now.
[1] https://www.pv-magazine.com/2023/10/13/solar-wafer-prices-hi...