Yeah; if just used for hot water, this doesn’t make much sense compared to a hybrid heat pump water heater. Here in California, with a well insulated/partially passively heated/cooled house, our hot water is well under 10% of our electricity bill (ignoring our EV).
In places where it’s really hot or cold, it would be an even lower percentage. The money that it would cost to trench and maintain the hot water distribution lines for a house would probably be better spent on heat pumps, architectural features or upgraded insulation (Even just $2000 of extra insulation does an amazing amount of good vs. bare minimum code insulation, and I doubt you can get district hot water installed for less than that.)
In places where it’s really hot or cold, it would be an even lower percentage. The money that it would cost to trench and maintain the hot water distribution lines for a house would probably be better spent on heat pumps, architectural features or upgraded insulation (Even just $2000 of extra insulation does an amazing amount of good vs. bare minimum code insulation, and I doubt you can get district hot water installed for less than that.)