I think you might possibly have either missed or misunderstood these words in my post: "...except the elite and sub-elite levels".
Nope, I understand it perfectly - its just that you are wrong... completely wrong.
Where do you think elite athletes, and sub-elite athletes come from? Do they just magically appear out of nowhere like fairy dust? No, of course they don't. They come from the grass roots of every sport. They are the ones who strive hard to succeed, and so through sheer skill and determination make it to the next level, and the next, and the next an so on. Only a tiny percentage of grass roots athletes ever make it to the next level, and only a tiny percentage of those make it to the next, and so on.
It is at the level of grass-roots in women's sport that having transwomen competing against women
will do the most damage to women's sport (and let's not piss around with all the PC semantics here - however you try to spin it, transwomen are physiologically male). Bigger, faster & stronger transwomen
will dominate women's sports at those levels, there is zero doubt about this fact. It is already happening now.
That domination
will lead to women being unable to progress in their own sport, and this
will lead to transwomen being the ones who predominantly progress up the levels thanks to the unfair advantage of their male physiology. Ultimately, the women trying to compete in women's sports will have no chance of progressing, particularly in individual sports like athletics, where select is based on times and placings.