My first apartment was filled with those!
I had a platform made out of them for my bed (with plywood board and a mattress on top), multiple shelves made from boxes and boards where I kept my clothes (folded) My kitchen table was a platform made with them with a board on top, and more for seats...
I lived on bananas and potatoes and cheerios with all this, while working full time and paying for college full time
My late Grandfather sat me down when I was a junior in college and taught me how to make steak, chili (and it’s cousin spaghetti) and roast. My grandfather was a double widower, and had decided that his grandsons would by God learn to cook SOMETHING so they wouldn’t have to eat fast food till they got married.
I would make a roast on Sunday and eat off it till maybe Wednesday. Then a big bowl of something with red sauce till the weekend. Never fancy but I ate.