Yes, agree with your thoughts. My car is new enough and low mileage enough that I wouldn’t expect wear other than bedding in perhaps. The vertical / rotational movement in mine is really very tiny but just discernible by gently touching it whilst the steering is turned under load. There is no lost steering movement at all, certainly nothing to worry a MoT with. I think it’s a TADTS issue.
What I would like to know is at high mileage can they be repaired / rebuilt and by whom? I had a Lotus Elan rack rebuilt by a firm in Birmingham but don’t know if they would do these.