Did you know that many people wear tube socks for medical reasons too?
One of the most common instances is that of diabetic tube socks. Diabetics are very prone to foot ulcers, so it's important that they have a good, supportive sock that can wick away moisture and keep the foot clean and dry. Unlike regular Hanes tube socks, diabetic tube socks are also made with a non-binding top, which is important, since diabetics often have compromised blood flow to their extremities.
Whereas a regular, top bound sock could cut off circulation and lead to foot problems, a diabetic sock is specifically designed to avoid this problem.
Some people also use tighter tube socks, like nylon tube socks, as support for varicose veins. Oftentimes, varicose veins become less painful if the leg is tightly supported, so this can be a good "band-aid" until further treatment can be taken.
Finally, tube socks are great for flying. There's always a risk of blood clots in the extremities, especially the feet and legs, when flying, and tube socks can compress the leg to help prevent that.
Who knew there were so many uses for the humble tube sock?