In many jurisdictions the cost of delivering a kilowatt-hour is already more than the cost of producing it. So cheap energy is not going to have a substantial impact on normal people unless we switch to wireless electricity delivery or something.
Energy costs might drop an order of magnitude, which is significant, but isn't going to cause any sort of systemic change.
See: https://reneweconomy.com.au/why-god-parity-will-be-the-end-o...