The Tavistock admitted they didn't have a way of telling the teens who were genuinely trans from the ones who were disturbed, confused or otherwise had another issue going on. They were supposed to filter the latter group out but got so carried away with trying to 'do the best for trans kids' they forgot to think about how you protect the non trans kids getting swept along in the same wave.
The question is, how many kids do you harm along the way with this inability to tell the difference.
The problem here is that, even if you believe in being trans, detransitioners are a reality. That's way so much effort is put into silencing or abusing detransitioners.
There is evidence that if left to it, a very high number of trans identifying children ultimately desist.
If 80% desist but you have a policy of transitioning before this natural desistance point then even if the 20% who would never have desisted 'get the appropriate treatment to live their true trans life', you've harmed the other 80% to achieve this goal.
In any other medical scenario this level of harm is clearly not ok. You wouldn't do a screening programme and then treat all the people who got flagged with an 80% harms rate.
Even then the treatment we are talking about has huge rates of complication and the treatment might well be worse than not treating in many cases. There is an assumption that intervention is always best which we are now conditioned to. This isn't necessarily true.