Really doesn't surprise me. Separation of sports by "men and women" is extremely binary. You can even see cis women with naturally high T levels compete in high level sports. Trans women aren't even allowed to win without feeling like they lost. Bigots make them feel like they cheated regardless.

It's not binary. There are absolutely physical differences between men and women. To deny this is to deny reality. You can go ahead and make the argument that if T levels are suppressed or kept even, that those advantages go away. But to claim that the separation of men and women, in quotes, is binary (which I don't really know what you mean when you say that), is foolish. There ARE differences. Just because the most athletic of women are more athletic than middle of the road men, doesn't mean there aren't differences. The ranges of the two have much different floors and ceilings. There is simply an overlap between those ranges.

What about men who are taller than average cis women? Do they not have a biological advantage in, say, sprinting?

Is there some reason that that biological advantage isn't important, but any biological advantage a trans woman has is? Is there some reason that categorically banning trans women makes any sense it all, with no consideration to actually measure any advantages an individual trans athlete has?

Some consistency would be nice. How are we going to define what a cisgender woman is in specific biological terms? Are you no longer a cisgender woman if your lung capacity is too large? What about if your wingspan is too wide? Are you still a cis woman, if you have a mutation that gives you significantly wider wingspan than an average cis woman? Why are those advantages a-ok on cis women but immediately a problem on trans women?

If we're going to control for "biological advantages" then it'd be nice if we actually did that at all. Instead we're just talking about categorically banning trans women. Gee, I wonder why that could be? Couldn't have anything to do with the global conservative movement pushing transphobic narratives and attempting to have trans women ejected from all women's spaces and legally forced to live around and as men, could it?

Firstly, certain groups have over politicized this topic in order to punch down on a minority group they dislike. Those people are ass holes, and I'm not defending that behavior. However, unfortunately, their base argument does actually have some marret, even if they are complete ass holes about it.

There is consistency, to use your terminology cis gender women can compete with cis gender women & cis gender men compete against cis gender men. Transgender folk are somewhere around 1% (or less) of the over all population, they are the extreme outliers that don't fit this consistent & highly effective (in terms of athletics) categorization of men's & women's sports. Another group, roughly the same size with an unknown advantage/disadvantage that are excluded from this classification are amputees/augmented humans.

We currently have separate competition for amputees from non amputees, the Paralympics exist & is lauded as a good thing. Outside of the political oppression issues, this model makes far more sense for trans athletes then simply allowing them to compete with the gender they identify with.

Splitting competition into male/female makes sense, because sexual dimorphism is a reality for our species. In nearly every sport, women are highly disadvantaged against men. Statistically the physical divergence between the sexes is vastly larger then the divergence within the sexes. This is consistent, despite your argument to the contrary.

I'm all for trans people being treated with respect, but respect goes both ways & part of that respect is the admission that a trans woman is not the same as a woman, and a trans man is not the same as a man. These are 4 different & distinct categories of people (hence the desire to relabel two of those groups with the 'cis' moniker), and ignoring that reality causes more problems then it will ever fix. It is not transphobic to prefer dating cis gender people, nor is it transphobic to believe that men & women's sports should be for men & women respectively. Both of these CAN be transphobic if your being a hateful dick about it, but it's not inherently so in holding those opinions.