Realistcly how much can be cleaned out of a house, as a child of a hourder?

So this is kinda of a follow up from one of my older posts, but you can say im a child of a hoarding family but some of its my fault aswell. My mother believes we dont need an external help and that i can do it by myself as if its my problem, which bugs me and demotivated me knowing how lazy and annoying m family is.

Im here to ask what should i do, i would move out but i cant. I want to know the math behind how much clutter one person can get rid by themselfs, and how much time it would take. its not like the stuff you see on tv and theirs no rotting food but still. I also would like to know how to get motivated and stay motivated?

What would you advise i do?