Donning and Doffing is "changing clothes"

Today the Supreme Court decided ( that putting on personal protective equipment like "a flame-retardant jacket, pair of pants, and hood; a hardhat; a “snood”; “wristlets”; work gloves; leggings; “metatarsal” boots; safety glasses; earplugs; and a respirator" was changing clothes. Why is that important and worthy of attention by the highest court in the land [...]