As soon as one of the tenets is conceded the whole edifice starts to collapse.
Because it's built on faith, on articles of faith, not evidence. Either you accept Transwomen are women and trans people are holy and not subject to the same standards/laws/rules as other people; crucially, without ever admitting that these are faith based positions, or you have to concede that these are faith based positions, and therefore you have to acknowledge that they are not material reality that one can base law, rules, or science/healthcare on.
Look at the debate in the Commons. The only points anyone could try to make to counter Cass were either fallacious (Dawn 'they based the report on two studies' Butler) or sentiment-based (Stella 'trans people are terrified' Creasey) or empty platitudes (Zarah 'trans rights are human rights' Sultana). They are all faith based catechisms. They don't mean anything, or they are clear and obvious mistruths.
Once reason gets a foothold the rest of it comes tumbling down. You admit that puberty blockers are not reversible, then you have to admit that the use of them is not based on evidence, then you have to admit that 'transition' is not based on evidence, then you have to admit that 'gender' is not a real, solid, measurable, describable thing.
It may happen slowly, but that is the tip of the wave starting to form.