[Vaquero]

XX = female
XY = Male

Nothing else counts. It’s just a fantasy. Wanna play dress up? Knock yourself out but it’s doesn’t make them something other than the sec your were born with.

[JohnBovenmyer]

If 'you' have zero Xs, regardless of Ys, 'you' aren't alive.

More generally, if every chromosome is intact and working normally, Y matters:
Got no Y, no matter how many Xs, you're female.
Got 1 or more Y, no matter how many Xs, you're male.

The common 'intersex' varieties are hormonal:
In Androgen insensitivity, males' testosterone receptors don't work. Male bits under to nondeveloped.
In Congenital Adrenal Hyperplasia, females overproduce testosterone, making female bits masculinized

There are some extremely rare others where bits of sex chromosomes relocate onto others or other genes are mutated but the above two account for most of the confusing ones after birth inspection.