Geothermal is not uncommon here in Sweden, I think that some goes deep instead of wide maybe because we have a lot of rocky ground which is easier to drill into.

But like your article says the installation is too expensive for the expected savings. There is another problem you didn't bring up and is scalability, geothermal works fine for detached houses but not so great in a city where most of the energy goes to.

District heating is a great solution for denser population areas, here we burn trash and solve two problems, and in theory it can be combined with Geothermal heating