Thing is mixed leagues already do exist although only at a amateur level which as you said starts to change the more the skill and physicality goes up..
What makes this while transgender push even weirder is that men's Sports won't be affected at all but woman's sports will be butchered as more codes of sport allow this sort of thing. It'll end up being men's Sports with blokes running about as per usual and then woman sports with blokes with wigs and bolt ons running around. Such a strange reality if it ever comes about.
Had to smile at 'bolt ons'. Maybe do some BoP (Balance of Performance) like in motorsport, air restriction, ballast weight or aerodynamics are also adjustable for humans.
All sports done with a mask to mimic a womans air intake and smaller lung capacity.
If you want to run the 100m you will be carrying a handbag with a bowling ball in it.
Long jump only with a kite attached to your waist.
The mindset to win in sports is connected to narcissism, especially in non-team sports. Anybody using their 'unnatural' advantage is acting peak unsportsmanlike. There were a lot of women being too good natured (or not on a career-torpedoing course) with grim expressions when that weightlifter took their hard work and shit on it. Kudos to those that do stand up against this buffoonery.