I'm certainly not here to defend the practices of GIDS. Imo it was a deeply flawed service in a number of respects, and there are legitimate criticisms of its consistency and clinical practice.
However, I think it's a mistake to characterise clinical practice as simply accepting every young person's self-description without assessment, particularly for those under 18. The overwhelming majority of children referred to GIDS were never referred for any form of medical intervention. I posted the figures earlier in the thread, and since the Cass Review and the closure of GIDS, access to medical interventions has become even more restrictive.
In practice, most young people received ongoing psychological assessment over multiple appointments often spanning years, alongside what was characterised as a "watchful waiting" approach. Those assessments were intended to explore their developmental history, mental health, neurodevelopmental profile, family and social circumstances, sources of distress, expectations, and the potential benefits and risks of different approaches.
Whether those assessments were always carried out well, consistently, or to an appropriate standard is a separate question—and one on which there has been substantial criticism. But that is different from saying that assessment existed only in theory, or that clinicians simply accepted every conclusion a young person reached without exploration. I don't think the evidence supports that characterisation.
There has been considerable debate and change over time in how best to support children experiencing gender-related distress. Some clinicians have argued for more cautious approaches, while others have argued that access to medical interventions should remain available to appropriately assessed individuals. I have not heard a suggestion that treatments should be offered without any assessment.
It is reasonable to debate whether particular guidelines have placed enough emphasis on uncertainty, evidence quality or alternative approaches, but that is different from saying clinicians are simply not assessing risk or that they are all acting out of ideological pressure. Those are claims about individuals' motives and professional practice that require evidence rather than assumption.
I think a useful question is not whether clinicians should always "affirm" or "not affirm" a child's experience in the abstract, but what form of assessment and support best helps a particular person given their own individual clinical presentation, available evidence and the uncertainty involved.