That's not really true. More so than just covering for night you have weather, and seasons which have significant swings in solar productivity. It not a baseload.
Distribute your solar across multiple geographic locations
> seasons which have significant swings in solar productivity.
Install enough panels so that in the seasonal lull you still have enough power. Panels are super cheap these days.
Solar panels and storage are on learning curves just like integrated circuits are for Moore's law. We are seeing absolutely astounding drops in cost every year, and innovation is happening continuously.
The future world of renewables energy is one of extreme energy abundance. We will size our generation so that in the seasonal lulls we have enough energy, which means that in the rest of the year we are going to have absolutely massive amounts of energy available that's near to zero-margin cost (assuming you can move your electricity consuming application to be close to the generation site, since transmission will still be expensive). And this curtailed electricity has far more potential uses than the waste heat that comes out of a nuclear plant or a coal plant.
Your wishy-washy handwaving style of argument is all fine and good for the internet but show me a country (or even a reasonably sized city) that's actually self-sufficient from solar and wind renewables (backed by storage).
Why do you think Germany is signing multi-billion/multi-decade contracts to ship Russian gas if solar/wind+storage is a solved problem?
