You are, in fact, wrong.

1. It's inherently transphobic to force trans women to comepete as men.

2. Medical transition does indeed affect those physical advantages. It is unfair to ask a trans woman who is taking testosterone blockers and/or has had an orchiectomy to compete against cis men in those sports which SHOULD be sex segregated (a lot fewer which are). It is also unfair to ask cis women to compete against a trans man who has been taking testosterone...in fact, testosterone is a restricted substance and trans men have to get a doctor's note to be allowed to take it. Including in sports which are NOT sex segregated...I know a trans man who is an equestrian and he had to jump through SO many hoops to be allowed to compete at all. In a sport which is not sex segregated.

I'd suggest doing a little bit more research before you make a blanket statement about superiority.