I have mild hoarding tendencies.
My mother used my things as a tool of control - she’d trash things like my stuffed animals, broke or threatened to break things that belonged to me multiple points during my childhood. I have a memory of being six and having all of my Pokémon cards thrown in the trash because I told her I hated her. Another time she ripped up a book (a Lord of the Rings omnibus) that belonged to my dad - lied and insisted that dogs had broke into my room.
Hoarding is about fear and control. I am afraid of having nothing - of losing everything, of having lost the the things that represent me as a person. My books, my art, little things I’ve collected. It represents control and safety. If my things are in a place, it means I have a place I belong and am safe in. Even if parts of my apartment can be unnavigable, even if there are piles of books and crafting supplies, those represent less chaos than stability.
So much of mental health care is about pathologizing rather than understanding. I would not react well to a therapist coming into my space and telling me I should throw things away. It would distress me immensely to have things thrown away. I don’t think my hoarding is at the level where it has an effect on my safety or health; it’s just not aesthetically pleasing to most. But so much mental health care at the end of the day seems less about honoring a person, figuring out what makes the individual feel safe and honored, and more about making the individual palatable to others.