Particularly for the Southern US, I feel that the costs will continue to drop until the transition will be very sudden, and there will be a rude awakening of sorts.
Solar panel leases are so long (50 years on top of the decade to interconnect), so they come with additional negatives as you are often signing up the next generation for a relationship that they had no say in.
Depending on what you're doing with your land, you can multi-use solar farm + grazing, or solar farm + some crops which increases it's value.
The rude awakening is when US customers used to buying $60k gas guzzlers are able to buy a $20k EV.
I don't this requires the loss of "superpower" status really. Already, if you dropped all EV, solar, battery tariffs in Florida, I think people there would be blindsided by how fast things start to take over.
At least the rest of the world is going to get richer in the meantime.