Power utilities frequently complain about declining base load generation capacity. On this particular issue, they are actually correct. You have to have a consistent level of base load generation capacity that is capable of scaling to meet peak demand. Wind and solar power are great but are not available on demand.
So, you can either store excess power generated by renewable sources or generate with non-renewable sources. Utility scale storage just isn’t there at this point. Many of the coal plants that have been retired over the past two decades have been replaced by natural gas plants, which isn’t really an improvement.
One thing that probably exacerbates this problem is the fact that much of the power generated in the US has historically been fairly localized. Meaning, it’s generated pretty close to where it’s consumed. Moving away from a “local” generation model is not as easy as it sounds and makes utilities nervous, for legitimate reasons.
What we need in the interim is more small scale nuclear development. It’s far from a perfect solution but it’s way better than what we currently have.