You have observed that a thing is done, which was already observed. You have not explained in what way it has a rational purpose, or added to the conversation.
It's not important. It's merely treated as important, which we already knew, because that was the setting for the question in the first place.
You may not like or approve of these things, but they are part of the "purpose" you seek.
If I had to choose to be in a foxhole with a fit 20 year old woman or a flabby 35 year old man, I'm choosing the woman every time. (Even the new, stricter, US military fitness standards are not that hard to meet for either gender)
Yes we established that this is the norm in the opening question. You're answering "we do that because we do that"