...why is it so much more than the energy required to charge slowly? The battery might get a little warmer while charging, so that's some more waste heat, but the battery gains the same amount of stored energy either way.
You could look into cheaper batteries, as there is no need to use the latest and greatest technology. Supercapacitors might also be an option.
It's all an economic sum, really: when do the higher connection fees and increased demand pricing outweigh battery cost? We are already seeing grid-scale battery storage being used in practice, applying that to a more local use case might not be that unrealistic.
Besides, if the alternative is no charging station, you can probably charge significantly higher fees.
The grid can never support a 100% EV demand. Nationwide, every single transmission line, transformer, and substation would need to be scaled up.
It is a pipe dream to do it in 30 years. I don't even know what to call it doing so in seven. Dementia is probably the most appropriate word given who is pushing it.