Good point about war, starvation, etc.
If we had to concentrate on survival, how many people would be wearing perfume?

Natural body odor tends to be more offensive when people are sick, not digesting their food properly, and so on.
Certainly, washing regularly will help keep that odor to a reasonably 'clean' scent, instead of a disgusting reek.

One time, I was sitting in rehearsal, and I smelled this spicy cooked meat smell. It actually smelled good! I then noticed that it was me, and several people agreed that it smelled good! (Nobody disagreed, either.)
If I eat meat, I really don't like the way I smell after the first 30 minutes, and when I'm sick, it is totally disgusting.

I have never found a shampoo that doesn't make my scalp and back break out in reaction to the scents.
Anyone have any recommendations for unscented shampoo?

My favorite perfume, which I only wear occasionally, is Sandalwood essential oil plus real Vanilla extract.
I just dab one drop on my wrist, and rub my wrists together. Sometimes I'll then rub my wrists behind my ears.
It smells like my skin, only sweeter.