@Doubledee511 thanks for reaching out with your question! These holes in the Achilles area, are they near the top or the bottom of the Achilles? That wear pattern up top is a common spot for socks to thin out. If the pattern is happening more towards the bottom, closer to the heel, it could be the result of a loose fit in that part of the shoe. As your feet pick up, the heel catches in back and causes some friction on that part of the sock.
This isn't necessarily indicative of a poor fit. If you are looking for new socks you might benefit from a pair with extra padding in the back.