I was talking to my union rep and found out exactly why companies are so against chairs. Back in the 1970s companies regularly provided chairs for stationary positions. Even in a lot of ads from the 60s the workers were sitting in a store. Sometime in the early 80s, when unions started to decline, managers started to take away the chairs. At the restaurant my rep worked in at the time when somebody got injured or unable to carry the trays the person would be moved to cashier and sit during their shift. When they moved to standing it pushed a lot of older workers out.
The companies claimed it's not professional but they're sitting at their desk while making this claim. For anybody too young to remember they gaslighted us, but the real reason we don't have chairs is because they want to push out the older workers and disabled workers.