So are you suggesting that only people wit DSD and an incorrect sex assignment should be allowed to transition if they wish?
I made no such suggestion.
I never accepted that DSD should be the only reason to transition.
And in addition many DSD's may not be diagnosed until puberty or even adulthood. By which time the gender might be too well established for the person to make a change.
Indeed some born with DSD may never be diagnosed.
In part, the discrimination shown towards transpeople may affect the decision to not transition.
So once again your assumption is dismissed.
For some data to influence your thoughts: there is, on current estimates, about 30,000 people in UK with DSD. (about .05%)
But there are about 250,000 trans people in UK. (about .5%)
that's an error of about 10 fold.
Of course there may be other simple explanations for the discrepancy.
Current estimates are based on current births and the medical ability at the current time.
But when the 250,000 trans people were born, the medical acknowledgement (and capability) of DSD, and the attitudes of doctors and parents was in its infancy (pardon the pun).
Even now there might not always be 'intersex' medical capability easily available. And some parents might not want it.