They're useful, ok? I'll use them!
But often useful containers look alike and then having a set of them means they'll tessellate well making the most of the space... and also they'll look cool!
Maybe I'll refill them with spice, it'll save us money!
Then of course some things have nostalgic value as well. I have fond memories of being allowed Golden Syrup drizzled on my rice crispies when visiting Nain and Taid. It's also the only food stuff that comes in paint tins.
Come the apocalypse I'll have to choose between using these for target practice or storage
And then sometimes containers contain good things and keeping them is a way to keep a sort of journal of your other hobbies. Bottles with cork stoppers are cool.
Referring to Gin as a hobby is probably a bad sign.
*except those 4 identical jam jars, they'll be useful!