Answer:
Iranians have bare minimum furniture in their homes. Although the modern housing architecture consists of furniture, but that furniture is usually low.
Iranians use low sofas or even use cushions on the floor to sit. They have dining tables but still they serve food on a soft cloth on the floor and sit around it an it.
It has medicinal benefits that came down from the ancients. Sitting on the floor with cross legged posture helps in maintaining the fitness of a person.