The present Mrs Hughes and I have slept apart for a number of years now.
This is for purely practical reasons - she likes to read until very very late, during which time she rustles papers, fidets, whistles, sings, gets up to the loo, and generally makes a racket - none of which would keep me awake for long, but probably subconciously disturbs my rest.
I on the other hand, snore like a nest of dragons, plus I dream vividly so I thrash about, cry out, and weep in my sleep.
So separate rooms are ideal for us - apart from 'visits' of course!
Culturally, rich people have, and still do sleep separately, because they have enough space to do so.
When people started city living with less space available, it became the norm for husbands and wives to share a room, and a bed.
When we go away together, Mrs Hughes and always book a king-sized bed where possible, and since we both read until the early hours, that's not a problem. I wear a plastic Snor-kil device which virtualy eliminates my snoring - I hate and loathe the thing, but put up with it for my lovely wife whom I love dearly.