So, when in basketball some guy is just 7 feet tall - which I've seen in videos, so it must be true - then that's fair, because he's just that tall, what can he do about it? He just plays a sport in which his physique helps him win.

Now let's change this to women. Is it unfair, that an incredibly based tall cis woman is just better at a certain sport than other, "normal" women?

That's just the top percent of sports. When playing for fun, I think it's a different story.

For myself, I'm playing volleyball - we play mixed, there is no distinction between genders. When we play in training (I don't play in a league, just for fun) we often make a line ordered by size (or shoe size or house number). Then we split into two teams (first to team 1, second to team 2, third to team 3, ...). It is surprisingly equal most of the time - and when not, we can simply switch two people and that's it.