They really aren't. Recently (2021-2022) Mexico conducted a large random survey of the population and their results were within margin of the oft-claimed 1.7% number (their rate was 1.3% for the sample). The paper linked does some further analysis on those results [1] but the raw data is available at [2].
And their survey evaluates intersex conditions as those present at birth (even if they are discovered later in life but were present at birth).
Wasn't that claim about people who had surgery (or a condition that is visible for which they usually intervened surgically) at birth instead of all intersex people?
I really don't think anyone considers the case of Kathleen to be intersex, seems more like a strawman.
