There's this school of thought that all are equal etc etc. Some people like to drown themselves in such thoughts and generalize like this because it gives them some kind of idealistic comfort. Those people like to say such things because it's the safe thing to say and is instrumental in inciting harmony among humans. Perhaps, it has some benefits when pooling resources / driving people towards a common goal. I don't deny its benefits in the right circumstances. Therefore, it's also not surprising that it is the mantra for human rights activists / feminists / leaders and they're correct in their specific goal oriented approach. But the key thing here is that the only thing common is the "goal" or the "right to certain opportunities" for specific groups in specific circumstances. Not even achievements are exact same in most cases, although they could be similar in some.

The reality however, is that hardly anyone is equal, in most walks of life and in the majority of circumstances. As far as similarities go, people of the same sex "just" have the same organs. There might be people unfortunate enough not even to have similarity in that aspect, with defective organs or absence of certain organs. Individual "representation", "ability" and "environment" may differ and that pretty much covers all the differences and there isn't much we could do about it either. Nor do I see any good reason why we should try to achieve that. We are here in this world only to do the best we can with what we "innately" have and our "materialistic gains" / "acquisitions".

Let us think about the aspects I mentioned.

"Representation" - Everyone clearly doesn't look the same, nor do they behave the same, way of doing things is also different amongst most sects of people or even individuals. On a superficial level, every now and then there are bound to be similarities. I'm not saying there could never be similarities but more often than not, even the similarities have some difference. But the way we eat, dress, go about doing our preferred things is clearly different in most cases, subject to similarities except some of the very basic or simple things. It depends on how detailed is your outlook towards the same. On a broader level, yes, all humans eat, sleep and do something in their life. But so do other animals. Does it make us the same? Clearly, not.

"Ability" - I don't think it is an unknown fact everybody's cognitive ability, memory, aptitude, reasoning, strengths, physical abilities etc do differ and there is no real way to quantify these things. That's why we have sports competitions to adjudge a winner and examinations for more academic evaluations and other aspects. We are always achieving or not achieving something in most things we do. In other words, we are "winning" or "losing". The fact that there is a term called "winner" and "loser" itself supports the premise that all are not equal.

"Environment" - Circumstances one is subjected to. Your environment certainly moulds you. That's why the way someone has been brought up, has an impact on what the person becomes. This has been tested in the animal world and the human world. In a confined environment, a bear, tiger and lion could live harmoniously together as that is how they are brought up, while in the wild, they would not be anywhere near each other. Progeny of the same parents, if brought up under different circumstances could turn out to be different. Similarly, practically in life, opportunities one has, company one has kept, the latter especially in the formative years, tends to have an impact. "Luck" is also part of "environment". The reason the term exists, is because it may not be same for all. Of course, there are things like "we make our own luck etc", but may not always be so.

Although the 3 above are different aspects, it can't always be said they are always unrelated. Sometimes, "representation" can lead to certain "abilities" or "opportunities". "Ability" could lead to "opportunities" and all or either could lead to "results". That's how things work in life. That's pretty much why we are individual, different entities. Being unified has advantages in certain circumstances to achieve a common "goal", but that is not a measure or justification for living beings being equal or their achievements being equal. At best, what could be somewhat equal / similar / equivalent are opportunities / rights for equivalent people in equivalent definable, somewhat simple, circumstances and the understanding / expectation we have towards that particular aspect. But that's where the similarities end and even that may not always be applicable.

Hence, people of the same sex or even people in a more general sense, are not very likely to be exactly equal, whichever way you look at it from an analytical perspective.