you done need rare earth minerals to store energy at a massive scale you need more of those https://www.electricmountain.co.uk/ but those aren't cheap, wont be build by private industry, and is so ancient a technology that the startup scene will play no part in it.

Otherwise you are right the really big problem right now is that we don't have a suitable replacement for oil that wont also change society in ways nobody is willing to deal with yet.

Fission is not going to be small and safe enough to really replace oil, fusion does not yet exists in the real world, so were probably stuck with renewable untransportable energy infrastructure for any future growth.