That's true, but "to humans" is a specific, meaningful, useful answer.
We are not yet bush robots or utility fogs or bit patterns whose
wills are unconstrained by our physical nature. Even if we did upload
our cognitive facilities /as they are/ into such a mechanism, the
values and drives pre-coded into the system are those that evolution
as a biological organism put there, and "attraction" is one of the
strongest pre-coded drives, because sexual selection drives evolution
faster than many other influences.
In my purely rational moments, I may conclude that spending time and
money on clothing is a waste of my resources, and I should therefore
spend my life in plain muslin robes that I might devote more time to
loftier pursuits. Perhaps there exist women with whom I might share
a fulfilling relationship who would be attracted to an unshaven man
in a plain robe, but I'm not putting bets on it. I am more likely to
meet interesting women if I dress in a way that women, by their nature
as evolved primates, are more likely to find attractive.
I might wish to decry the injustice of it, complaining that I have to
buy $40 shirts and spend time ironing them; just as some women may
complain about having to make themselves up to appear more youthful.
But personally, it is less effort for me to take advantage of the
world as it is than to try to change what we do not yet have the
technology to change. When it comes, sign me up. Until then, I've
got dry cleaning to pick up.