This question is loaded. Trans women are not really biologically male, depending on the time transition happened there will be varying degrees of masculinised secondary sex characteristics but things such as fat distribution, muscle mass, organ size changes etc are going to look much more "standard" female than male.

AFAB women aren't excluded from sport if they're unusually tall, or have PCOS, or some other hormone variation that leads to an advantage. Women with PCOS will have an advantage in sport involving strength because they have much higher levels of testosterone (some grow patchy beards ffs) but nobody makes a fuss over that.

All sport is inherently unfair, we try and set limits of degree of unfairness. There is no evidence that trans women have more advantages than all the usual variations in women we allow competition among without issue. The Olympics has allowed trans competitors since 2004, where are all the trans gold medalists? where are all the trans women winning everything? Have you seen the differences in male and female records for most sports? If trans women are meaningfully similar to men then the average trans women would just demolish many sports. This doesn't happen, only a few people have attracted attention for success and that's in an environment of media controversy with actively trying to seek them out.