You are being too dismissive of the unfairness being experienced by all the biological women who have worked for years to become elite only to lose out to a trans woman.

From the data, this almost never happens. To be sure, it will happen - but very, very infrequently.

Far less frequently than the instances of all the biological women who work for years and years to become elite, only to lose out to a cis woman who's an inch taller or has slightly wider hands or slightly more efficiently configured muscles.

It is nature of athletics that at elite levels, a lot of what happens on the podium is due to genetics and body shape - not just training or skill. Right now, all the evidence is that the delta added by including trans women to that existing genetic "happenstance" will be trivial. Not non-existent - but small enough that there's a pretty good argument that for now, balancing the equities leans towards inclusion, not exclusion.