The reason battery prices are down 97% since 1990 is because of better battery chemistries coming along.

Currently there's a few more in the pipeline (including silicon) that lead market forecasters to predict the long-term (think 2030) trend will continue.

The downhill road of pricing has had some bumps but it's very assuredly, extremely downhill

So Wright's Law applies to batteries but not to nuclear power?

Yes, that's what the historical data from the last 50 years supports.

Wait, that has happened with fission too, just not at grid scale because there hasn't been funding for it. If you look at military, academic, and space nuclear reactors, you will see Wright's law playing out. Solar and wind got the chance to ramp investment and scale. Grid-attached nuclear never did.

Personally, I see more risks to massive-scale battery production than to modest-scale nuclear fission, both of which solve the same problem.

The battery price graph tells a different story. Improvements have been slowing down for a long time, and have been almost zero the past couple of years and we've actually had a price increase this year. Switching to an entirely new technology is speculative at best, not all that dissimilar from putting all hope in fusion. Could work, but betting the future of the planet on it is silly.