The issue here is that people have no problem admitting that tall individuals have an advantage over shorter ones in basketball - but when someone points out that trans women may have an advantage over biological women in terms of strength and speed,

Key word that's often missing: "may"

The NPR article that you used as a source is pretty clear on this, that there's a group of trans women for which this (stronger and faster than cis women) is not true.

[some] people suddenly come out of the woodwork, calling it a lie or transphobia.

FTFY.

The issue here is that ....
Blanket bans are rarely the optimal solution

Actually, I suspect the issue here is that other folks - right-wing and MAGA in particular - take the a statement similar to yours, and run away with it to justify a blanket ban.

In other words, your original statement,

This isn’t about not wanting trans people in the sports and you know it.

Well, I don't know it. Perhaps the folks on the World Olympics have loftier ideals - I sure hope that's the case.

But there are folks that don't want trans people to be able to use washrooms. (See https://www.nbcnews.com/feature/nbc-out/no-link-between-trans-inclusive-policies-bathroom-safety-study-finds-n911106 which references the belief, while pointing out that science doesn't provide support.)

Hence some hypervigilance to keep those folks from taking over the conversation.

If instead they acknowledged the advantage but still argued for inclusion, then at least we’d be agreeing on the facts - and the discussion could focus on how to level the playing field.

True - the discussion really should be focus on inclusion, and of course a level playing field should only further the cause.