I suspect it varies by case, and expands if you try to analyze too much and wade into what may be rationalization after the fact. People don't always plan their

I suspect it varies by case, and expands if you try to analyze too much and wade into what may be rationalization after the fact. People don't always plan their actions logically, but come up with (sometimes plausible) explanations as part of coping. I think some (much?) hoarding is driven by a basic emotional loop that seems adjacent to agorophobia. Acting on an impulse to gather things around and live in the resulting "warren" seems to give them comfort. In hoarders in my family, I've also seen something like the "self delusion" you mentioned. They fail to acknowledge the time-varying value of most things, decay processes, negative externalities, or sometimes even opportunity costs. They almost seem to think they can avoid realizing a loss by never disposing of an item. Kind of a HODL (hold on for dear life) investment plan applied to material objects.