My uncle's wife was a hoarder. The lived on their own property, and didn't have visitors. Didn't want them, they made it clear.
When the truth finally came out, we discovered that they actually had to live in a garden shed because the house was filled to the ceiling with junk.
It was shocking. My uncle said he couldn't get her to stop hoarding, and he was too embarrassed to tell anyone or let anyone see it.
What a sad old couple.
That is very sad. I hope you're able to extend a hand and help them, despite their refusals (unless they passed). My mother-in-law was a hoarder. Father-in-law died some years back, the children grown up and moved out, and my wife's mom let the hoard accumulate. Until her mental faculties declined and we stepped in to care for her, taking her into our home while we cleaned up her house. Took us two years to clear out most of the junk. And it was junk, all useless unnecessary garbage. There are a lot of people with severe psychological problems, manifesting into hopeless situations whether hoarding or morbid obesity.