The Onion

Really depends. For people that never went through puberty of their birth sex there's effectively no difference in terms of strength.

After adulthood it's definitely debatable, after a few years of treatment physical capabilities mostly align but not entirely, and while unlikely it would kinda suck for the rest if someone did win olympic gold bc of anatomy differences or something (plus countries with a history of cheating potentially could abuse it by sending an athlete that is not actually on HRT). I also don't think the ability to compete in high level sports is anywhere near a fundamental human right.

However it would also suck for the transwoman in question having to choose between high level competition in the sport they likely poured their life into and transitioning (as there is no way a transwoman on HRT could ever compete at the highest level vs males in sports unless it's something where cis women can, too).

Personally I'd argue for pro sports requiring proof of consistent HRT for x amount of time (based on studies of at what point physical capabilitues are equal for the vast majority) should be sufficient. If against all odds we end up with a disproportionate amount of transwomen winning competitions (we won't) rules could still be changed.

At an amateur level it makes very little sense to restrict transfems, the difference isn't great after a while on HRT and so much of the point of amateur sports is usually on a social level that if you restrict transpeople from playing/competing with their own gender, you will often remove a large reason for wanting to do that sport in the first place.