What’s a biological woman and why do they matter more than ““non-biological”” women?

There are certainly female athletes with chromosomal abnormalities competing at any level. Women, who are completely unaware they’re in any way different because they have lived their entire life like any other woman. Women, who on average have a small boost in performance compared to women without chromosomal abnormalities.

Why should they be banned? Please elaborate and please also answer why this shouldn’t also apply to women of certain ethnicities with boosted competitive performance.