I don’t see the appeal of watching her win only because she is allowed to compete against women with much lower levels of testosterone than she has.

Let’s try adding your first argument to your second and see how it sounds.

“I don’t see the appeal of watching them win only because they are allowed to compete against people much shorter than they are.”

A genetic predisposition to success in a particular sport is either a problem for all sports or none of them.

If you are arguing that the current categories are what they are then testosterone shouldn’t be a factor unless you are positing that testosterone level has a threshold past which you are male.

The whole point of having a women’s competition is to prevent that.

The whole point of having a women’s competition is to separate “men” from “women”, if the point was to prevent unbalanced categories we’d be basing the categories on things that were important to the perceived integrity of the sport.

You could also argue that historically ( in the west at the very least ) it was partially to stop “women” from competing in “men’s” competitions, not because of a difference in physicality but because of a difference in societal expectations.

it makes no sense to allow a person with the specific set of innate physical advantages that men have over women to compete in the women’s competition.

Again, lets switch the subject of your phrase

“it makes no sense to allow a person with the specific set of innate physical advantages that tall people have over short people to compete in the short peoples competition.”

This is not a good argument.

As you said the theoretical solution to this is to based the brackets/categories on things other than biological sex, something that can be measured reliably and precisely, but also as you said , good luck convincing the public/advertisers to switch at this point.