Thorium and molten salt reactors are extremely hard to build because of corrosion from the salts. I believe newer designs (like accelerated neutron ones) can use the current waste and produce more fuel if needed.

I'd say they are not yet commercially usable on a big scale, but then again the same has to be said about battery usage for renewables.

The again, both areas need money and funding and I think it would be better directed towards storage solutions, because they don't come with the downsides of Nuclear. I have to admit tough that I am not well read about thorium rector, so if there are flaws in this view by all means point them out.