The process, per the article, is that a border agent makes a determination, and if it is not what the applicant claims, then a social worker takes over to make a final determination.
That is a massive time sink for social workers, and the appeal of having an automated system is pretty obvious. Considering that it is already all largely guesswork, I'm not really sure that "more accurate" is even an acceptance criteria for them right now- they'd probably be very happy with "mostly the same accuracy".
Of course, the social workers are opposing being taken out of the loop, but I can't imagine that there isn't already plenty of work for them elsewhere in the UK.
"a computer can never be held accountable, therefore a computer must never make a [legal] decision"
in my observation: when humans are automated out of a process due to the human element being inconvenient, the perceived efficiency gains are often because wronged individuals have less recourse in the automated system.
Purely curious if there's better ways, like I know X Rays can get us pretty close for children and adolescents, but that might not be the best way to do it, I wonder if there's other alternatives that are low cost.