Or do. Despite the many reasons you gave not to, I feel like it just depends on the person and their personal preferences, how “professional” they want to look, and how comfortable they are in a tie. They are definitely not a necessity, but I’ve worn a tie to every interview and have a career in IT, and I’ve only ever had one interview where I didn’t get an offer. Your interviewer is not going to dock points if you’re wearing a tie.