HTs firstly want people who are sympathetic and supportive of children, of other staff, and can treat parents kindly and responsibly, even when - as is often the case - parents are misguided, or downright rude, or wrong.
Having now looked at several of your responses to other peoples 'threads', I am afraid that you come across as somewhat abrupt, rude, aggressive and not at all sympathetic. It may be that your years in IT have given you that attitude, but it is not a quality that will be welcomed in most schools, I wouldn't have thought.
I was a TA (male) for twenty-five years, having started as a parent-helper, one day a week, when our DS started primary school. In addition to normal TA duties, I had recorder clubs for ten years, a keyboard (music) club with Yr6, gardening activities with Yr6, a percussion club for a while, and coached Yr2 children on percussion to accompany the Christmas production for ten years.
Compared to when I first started in schools thirty years ago, following twenty years in offices as supervisor or manager, the TA role was fairly new and has evolved a lot since then, with formal qualifications becoming more necessary.
One of my very first 'readers' turned up again, seventeen years later, in her final year of Teacher Training, and needed to supervise me in the classroom.
However, it is still the 'human' touch that is the probably most valuable attribute, and I think you need to work hard to try and develop that.