For one, very sunny places like California are getting very close to the "too much solar" on their energy production. Until microgrids take off, this is going to be a very serious problem in the next 12-24 months. California will probably have one of the lowest kWh/$ rates in the country during summer daylight hours. But off-peak hours will be much more expensive. Adding more solar would not help in these places because it would interfere with the economics of mass power production. The investment to build power plants (nuclear or gas-fired) is too high when you can only run that plant during night-time hours but sit idle during the day. Texas has been in a similar situation, before the Feb 2021 disaster, they were giving away free power at night because of too much wind production. All of that energy production has to go somewhere and grid-scale energy storage isn't feasible just yet. If it's not consumed, then it's just wasted.

Two, the tech is just forming to help solve some things, such as "floatovoltaics". Covering Lake Mead will help, or the Great Salt Lake in Utah. But water is very corrosive. Engineers have also stayed away from putting power lines in water for good reason. The tech for floatovoltaics is just now emerging, and even the national electric code has just put something in it for 2023.

Three, raw materials shortages. Solar requires a lot of silicon, aluminum, glass, and steel. Batteries require a lot of rare earth metals from harmful mining practices. You need billions of tons of copper just to handle the wiring and distribution side of things. Almost all lithium battery and solar manufacturing is overseas in China. There are some in the U.S., but not enough to make a serious dent in solving the overall problem. EV batteries have secured over 140% of the available lithium mines in the world. Alternative batteries like sodium-ion are exclusively produced at scale in China, but startups like Natron Energy are trying to change that (again, not enough to make a dent). But the main point is that there isn't enough lithium, cobalt, nickel, copper, silicon in the world to go around without having some serious inflation and supply chain issues along the way. The tech doesn't yet exist for grid-scale energy storage that doesn't rely on lithium and its closest cousin sodium-ion doesn't have the manufacturing scale to produce the billions of cells annually needed to tackle this problem.

Four, the U.S. lacks political will. Republican states are actively damaging companies who are reducing their carbon emissions. Fox News labels climate change as "woke politics". Thus, you have 40-50% of Americans believing solar panels and EVs as "bad" things. It then trickles down to local politics like where the article shows that Southern states should be accounting for 33% of solar production, but due to poor politics/laws they only account for 7%.