In addition to other comments here, I think that there’s added risk to having such a starkly segmented way of running things. Having neighborhood stations (publically owned/owned by the utility service provider) reduces a lot of redundancy and hedges some risk for families. If a battery fails and gets spicy it’s less likely to put a family out of their home, when a substation could be highly specialized for managing that kind of risk so that even if a battery or several batteries fail, it doesn’t impact the whole. There’s also some specialization that goes into handling them at end of life, and trusting normal every day laypeople to both maintain and manage them is a tall ask when most people find themselves in a position to be unable to do larger maintenance on their homes already (it cost me 20k to put in a sump pump and encapsulate my crawl space to treat and protect it from mold and pinhole beetles, which I could only do by taking out a loan that I’m still paying for).