They're actually trying to have it both ways - they do argue, as you just did, that women's sports are "segregation" and the result of women being told they weren't allowed to compete, for a variety of reasons.
So a lot do argue that the segregation should be ended and they should be reintegrated, and then the best person will win, regardless of their sex.
(And if women are currently worse, it's mainly due to lack of opportunity - when they get to compete with men, and given equal training and resources, there's no reason they couldn't fulfil their untapped potential.).
But they don't argue that very loudly - that's the "extreme" position. They mainly advocate the "moderate" one - given that the current division isn't going away yet, and it is an arbitrary segregation, the least you could do is let people into the division of their choice for now.
So everything you've just said they are aware of, and it's how they justify it in their fuzzy little Woke brains. They look at the "segregation" history and ignore the fact there are two fundamentally different body configurations, and mixed sport would render the people with female bodies uncompetitive.
The segregationists who said women were "not strong enough" were right, statistically. That exclusion could be reversed - making sure the "men's" events were "open". And many actually already are! But opening up the "men's" events to women doesn't eliminate the value of women's events for wider inclusion, just as allowing Paralympic athletes into the Olympics doesn't eliminate the value of the Paralympics.
There are lots of people who are not able-bodied males - it should be possible for the non-able-bodied and females to compete with and win against their peers, and not only be rewarded if they can beat able-bodied males.
(If I was Woke I'd say insisting people be judged by able-bodied male standards was bollocks-normative or something).
It is a significant problem that we just don't see much mixed-sex sport happening, so you don't often get to see elite male and female athletes alongside each other like this:
And a lot of people just don't do physical work themselves. People don't routinely observe the male-female difference. I don't know a male athlete's excuse would be though. Do they just not notice the women's events at all?