EDIT: I misread "ripping out these energy storage devices" as https://en.wikipedia.org/wiki/Storage_heater https://en.wikipedia.org/wiki/Storage_heater which ar

EDIT: I misread "ripping out these energy storage devices" as https://en.wikipedia.org/wiki/Storage_heater https://en.wikipedia.org/wiki/Storage_heater which are basically bricks with nichrome wire. You're right, of course heat pump water heaters use tanks to smooth out DHW demand, but that same thing isn't feasible for space heating.