Too many choices? And too many overlapping choices?
In the old days, many had one backpack, one tent, maybe a couple of jackets, and a pair of boots. And they hiked.
With time, more options were presented and folks began to enjoy lighter weight gear, clothing that dried more quickly, etc. And they hiked.
Somewhere along the line -- some folks let themselves become convinced (slick marketing brochures?) that they needed a wide array of gear -- as well as depth of choices within each type of gear -- in order to "dial in" just the right match and comfort -- before they can really head outdoors!
It's all subjective, of course, but I think many of us just plain like to buy gear -- we want to eliminate any perceived "gaps" -- and get the warm, fuzzy feeling that we're "all covered". Except sometimes, some of those "gaps" are more for hikes that we "could be doing someday, maybe" -- and not really hikes that we actually or are likely to do. But we like to "be covered" just the same...
In a nutshell, I think we find our gear closets hard to organize because we buy too much and delineate too narrowly??