If we can make energy storage simple and cheap enough I do not see why nuclear power would have any upside left except maybe for when traveling outside the solar system.
Regarding survivability of humanity I have similar fear but my current hope is that while weapons will continue to be more attainable their relevance might diminish. Why fight your neighbor if you have everything you need? But warlords create a problem of their own because they seem to exist to attain superiority for its own sake.
If we can make energy storage simple and cheap enough
If you're thinking of big Tesla Powerwall-style batteries, that just kicks the problem ahead by a few years or decades.
The materials needed to make those batteries are finite. They will become "the new oil" in N years.
Energy storage is going to be a big part of any sane energy future, but it's going to have to make heavy usage of non-battery means: giant flywheels? Pumping water? I don't know.
You're right that the current state of battery tech is woefully inefficient for any kind of grid-level storage.
But energy can be stored by pumping heated water to deep wells in the bedrock for example or you can use excess power to generate hydrogen and feed it back to the grid via fuel cells when needed. All of this is doable, but also slow to build and currently expensive.
What percentage of batteries are actually recycled? How much energy does recycling them take? What toxic byproducts are produced as part of the recycling process? What will future demand for batteries be, and how long will our supplies of lithium etc. last? Who controls the lithium supplies?
This is not an argument against recycling batteries, by the way. Chemical batteries are a big part of the future, and we should recycle them. But let's not be glib about any of these choices.
> Why fight your neighbor if you have everything you need?
Clearly this line of logic is not working, seen in Ukraine. At some point there is a person with enough power who wants to fight just because they can. Essentially humanity is at mercy of random power-hungry sociopaths to not bomb the nuclear power plants.
Regarding survivability of humanity I have similar fear but my current hope is that while weapons will continue to be more attainable their relevance might diminish. Why fight your neighbor if you have everything you need? But warlords create a problem of their own because they seem to exist to attain superiority for its own sake.