From what I have read of anthropology, tribal people (hunter gatherers especially) seem to believe that when you dream of a place, you go to that place - or your spirit does. This belief seems very sensible, and - with a few qualifications - probably more true than not.
My general perspective on dreams is that they are very important, but remembering dreams is not very important - they do their necessary work at an unconscious or subliminal level. The few and infrequent dream fragments we recall on waking can therefore be misleading. However, they are all the evidence we have.
I have certain places where I go in my dreams - and each tends to have a fairly typical mood or type of event associated with it.
Firstly, none of these places much resemble the 'real' places. So, when I dream of Durham Castle (which is a university college where I lived for a year) it has negligible physical resemblance to the actual castle - it is some kind of essence I dream about. The Durham dreams are always enjoyable and somewhat inspiring - which is my attitude to the place itself.
When I dream about Newcastle upon Tyne (where I live), I am often discovering some new and wonderful place or building that I 'never noticed before' - although last night I had the opposite kind of surprise, that the West End of the city (a street I lived while a student) had become a site of social collapse and violent strife.
(But, to be fair, that was one of those maddening dreams when, for some reason, I lacked shoes and socks - and pretty much anywhere is threatening in those circumstances.)
I quite often dream negatively about Glasgow, dreams with a sense of oppression and meaninglessness - which are a fairly accurate encapsulation of my state of mind during the time I lived there.
(Glasgow was certainly bad for me; but probably for reasons having little to do with the place or people; and mostly to do with my own wrong attitudes, beliefs, weaknesses, and basic unmarried and living alone situation.)
In contrast, I have recurrent delightful dreams about Oxford - which is a city where I have spent many weeks over the decades. Although I love being in the places, walking around, visiting bits and pieces; in real life, I regard Oxford university as mostly a corrupt, dishonest, mediocre and not just useless but actively-very-harmful institution - however, in these dreams it is a kind of paradise of true scholarship and religion (as indeed it has been, through much of its history).
Most of my dreams that I recall are simply those dreams at the end of the night's sleep, from which I am pleased to wake - cyclical and irritating dreams, seedy and violent dreams, dreams of oppression and dementia (the way in which life, especially memory and understanding, keeps slipping away from me in dreams seems like a taste of dementia).
I assume that the purpose of these dreams is vicarious experience of temptation, pain, fear, cowardice, hatred and other types of evil, so that I know these states not just theoretically. And this, although horrible to go through, I presume is one of the potential benefits of a prolonged mortal life. After all, CS Lewis had terrible nightmares all his life, and I infer that much of his vivid writing on evil was a direct consequence of these dream-experiences.
But do I go to these places? Is my body, lying there in bed, one from which the spirit has departed to another place? Am I away voyaging, and often suffering?
Well, yes to all of these; somehow, in some sense.
Therefore, sleep is not a waste of time!
Sleep is not an avoidance of experience but a form of travel, and a valuable balance to waking experience. Not something to be minimised or to be ashamed-of.
Sleep is a biological necessity, a psychological benefit - and probably has great religious significance as well.