They like it because it is cost effective, large complexes will have underground steam from a central plant to each building, sometimes underground chill water also.
Along with you can transport heat with water or steam.
Air is very inefficient at carrying heat.
Insulate the pipes and cities move steam for long distances,
hot air runs soon get cold. We have a co-gen electric power plant
that provides steam to a nearby city. They pipe it about a mile to get to town,
No idea how far it goes. If you tried to push hot air that far, it would be warm air at best.
