I haven’t used one in decades. I will definitely get rid of stuff if at all possible, rather than pay to store crap I am unlikely to use.

I had one briefly when showing a house I put on the market. Once that sold I used it to stage the move into my new house. It was initially filled with the stuff that made the house look cluttered: treadmill, bicycles, boxes of textbooks, etc..
When I was 20 the little rock band I played in rented one for a practice space.

I have a small storage area that came with my flat. I keep two bicycles there and a few odds and ends. I have never paid for storage, I have given things to relatives, to friends and to charities or I have thrown them out.

My old company still maintains a storage unit. Not much of value in it, mainly things that were left over from various construction projects. Will probably quit paying on it soon.

I do not. It’s a waste of money and most people never go back to that stuff anyway.

My parents briefly used one when we had our garage re-built, but that’s it.

I read an article a few years ago that said there’s enough storage rental space in the U.S. to store every man, woman, and child in the country. Why do we hang onto so much stuff? Why do I? And would the world collapse under the weight of it if we all threw it out on the very same historic day?

I have some stuff in a storage unit that I’ve overpaid for for a long time. It includes a lot of paper (files from an organization in which I was active for many years), some assorted relics and souvenirs that nobody needs, and a considerable collection of stuffed animals that my son took off his bed one day about 20 years ago but wasn’t ready to dispose of. I think there’s probably more dust in there by now than anything else.

I guess I have to go back there one of these days and trash all of it. My heirs would be neither horrified nor delighted—no corpses in a trunk, no priceless paintings wrapped in brown paper—but they would probably grumble a lot if it were left to them. I don’t believe there’s one single thing that the facility owners could sell for a buck if the contents were forfeit.