Those particular ones might be a waste of energy, but outdoor heaters like that in general are great for in front of hotels, and in the vestibule for doormen at clubs or valets

I responded further down but the infrared equivalent to these are very useful and explicitly solve for the energy waste issue you describe. Infrared heaters can’t heat open air which means heat-energy is transferred right to solid surfaces. It is extremely efficient in areas with any amount of airflow as the heat isn’t able to be blown away as it’s radiating from the surfaces below the heater, not the heater or the air between.

I bet we can take it even further. Switch it out for a phased array of infrared emitters that track and target people based on body temperature. Then it won’t have to be on all the time and there’s no way it could possibly go wrong.

Nah we can go way further, what we need is to switch from infrared to microwaves. By emitting microwaves at the right frequency, we can directly transfer energy in a super efficient way. We could tune it to make water molecules vibrate and turn that energy directly into heat. Since humans are basically bags of water, they’d be pretty warm without much energy required at all.