The problem with most 100% cotton socks is that they don't maintain their shape well, and they don't stay up. As the day goes on, they tend to bag and to sag; and these tendencies are enhanced with every washing that they go through. That's why most cotton socks aren't 100% cotton; the cotton is instead blended with between 15% and 40% nylon (which also improves the durability of the sock). Facenti socks aren't in any way normal, however. They're 100% cotton, and they feel and look great. They also stay up. All day. Even after several washings. I don't understand how they manage to accomplish this, but they do. It's a miracle of technology.
Facenti is a venerable Italian company, manufacturing socks since 1923. They're virtually unknown in the United States, however, although they are apparently trying to break into the US market. Here's to hoping that they succeed. They make a sock demonstrably superior in construction to Pantherella, the mainstay of the US luxury sock market, and Facenti's design sensibility puts Pantherella's to shame.