Backpacking. I have a big plastic bin filled with equipment that I decided to go another direction with.
But makers are the kings of hobby hoarding, just look at Adam Savage. He has parts for things he hasn’t even thought of building. He has a plethora of tools that overlap entirely just because the set of tools is closer to a given work aspect. Walls of bins with various degrees of filled because he bought 100 of something a decade ago that may have a future use.
Or what you put in a storage unit that is inconveniently far away. I still need those 5mm magnets…