Maybe it is just me, but I find that too often I cannot find what I want and I have to settle for what I can find. Manufacturers tend to make what the largest group of consumers want, not the small groups. Perfect case is socks. I wear a 13 shoe, but socks are for sizes 8 -12. Don't ask me how a size 8 can wear a size 12, but that is the expectation. Anything outside of that range, tough luck. I am sure I could find a specialty store that perhaps has larger socks, but main stream not a chance.
If your foot is size 13 you needs socks that are size 15 because of course shoe and sock size are different.
Go to oddball.com Their socks start at size 14 and up. They often have 20% off sales codes
https://www.oddball.com/socks