While people acquire items over time, I did the calculations and it's cheaper to sell and give items away and buy new again than to ship items from Europe or Australia to America. Try it yourself. Look at your books, appliances, furniture, clothing, whatever, and see if it’s worth bringing or replacing at £3 / AUD$5 / USD$4 per kg (about half that per LB).
By contrast, I lived for a couple years out of my suitcase in Japan. Just look at the size of my central Tokyo apartment in the video below. I happily lived out of a small sized backpack when I backpacked around Asia and lived in Hanoi, but I knew that was all temporary, so I paid a premium for furnished homes. I had no sympathy for my friends who complained they had too much junk. I was busy envying them for having useful everyday items I simply didn't have.
One friend living in her third country who loved living light occasionally played a game called "10 Things," where she would go around the house and get rid of 10 things she hadn't used in a while and didn't really need. Try it yourself, it's great!
Edinburgh was frustrating though. I was reluctant to buy anything to ease my life, knowing I was there for just a few years. Purchases would be a waste, and disposal a hassle. But an American/European couple in Edinburgh whom I was friends with when we all lived in Tokyo put it to me this way: if I do end up buying something, best get it early on, as later purchases will get less use. So I did buy a few things, and was all the happier for it. And that's how a friend was gifted a lovely air-fryer when I departed.
Being able to buy things in the US, while painfully expensive doing it all at once, also felt great. I am finally able to have practical home items, from a blender to a giant shoe horn, and all sorts of things. Owning more than two pairs of shoes still feels weird, but I'm still constantly appreciative of all these little things I wanted for years, and I'm still good at not acquiring junk. And no, I still don'd have any sympathy for people who complain they have too much stuff!