It’s uneconomical in an already built out area or a non central planned economy, and also the US is special case since we have dirt cheap natural gas that is used for heating.

Digging up streets to run distribution lines, running service drops to every existing house, installing a heat exchanger and valves in every house is astronomically expensive given the amount of energy used by a single residence.

If you’re building out a new neighborhood on a greenspace plot, installing the district heating/cooling piping is much cheaper since you’re already laying electric, water, sewer, and mane gas lines.

At least in parts of Eastern Europe (especially the former GDR) district heating systems were introduced as a response to the oil crises of the 70s, resulting price shocks and the transport of coal to households being very labor and resource incentive [1].

[1] https://www.ndr.de/geschichte/schauplaetze/Windkraft-und-Erd...

"I don't know how economical that is"

Sure you do. Think about it. Its just drilling a hole and making electricity from the heat. We have been able to do this for a very long time. So if people aren't really doing it much, its not economical. If it was now becoming economical, the article would describe some new way of doing it that makes it economical. The article doesn't, so you "know" it isn't.

PS This has been tried many time, it only works in very specific situations, usually places where building a full PP doesn't make sense or where you are making a lot of electricity for some other purpose (mining usually).