You don't need a physical explanation, rather a psychological one. People are generally bad at planning what they need. Taking a planet along ensure you have all you might need at reach. A starship might not fit all.
I am a cyclotourist and in my free time I enjoy doing multi days trip. This has teached me to travel light: in 2 panniers I can take all the needed for a 2-3 weeks trip.
Two years ago I was in Japan, climbing on the top of a mountain to visit a temple-city, where visitors are allowed to spend the night in the temple premises and practice meditation. As said, I was there with my bike and two panniers. Next to me there were 3 women, all in their late 20es, each puffing and panting to move 2 extra large suitcases where they supposedly had packed all they "might" need for just one overnight stay.
Some years ago I was to a 2 days off site with several colleagues: I had all the needed for 2 days in 1 sport bag. Some colleagues had 2 stuffed trolleys with them.