I also find hyper-specialist shops in america wherever there is still cheap land enough for it. When I used to live in Buffalo, there were small shops- one specifically for new agey "gypsy" clothing, one for bath soap made in house, one for herbs for witchcraft, one that specialized in stones. I really enjoyed those places and miss them now how I live in NYC (although NYC has its own quirks- big gay ice cream is great!)
New York City has tons of these too; they’re just generally not well-advertised since they many of them cater to a specific market. There are a few button stores in New York, mostly in the Garment District, but also on the upper east side. There are stores selling all kinds of obscure art supplies, kitchen equipment, and lab gear too.
To be fair, I’m not sure exactly where you’d buy a currywurst cushion, but there’s a shop selling bones and stuff near NYU, if you someday decide that your living in room needs more of a Natural History Museum vibe.
There used to be a bone store in Berkeley, called The Bone Room. They're online-only now, though, after the death of their founder and presumably also rising rents. (https://www.boneroom.com/about--contact.html)
The difference is that you'll find specialists in Germany even where land isn't super cheap. I remember really enjoying Stuttgart a few years ago because I hadn't seen any supermarkets. I'm sure there's a Lidl and whatnot but instead we stopped by a green grocer, bakery, and butcher for dinner.
In Berlin I'm not surprised there's a meat furniture store.
Chicago had a button store in the last ten years or so, but it is gone. It became a Barneys New York.
Roaming through the Nevada desert a few years ago (Tonopah area, I can't remember exactly where) I came across a small town with a book store that sold nothing but old 1940's-1970's cowboy paperbacks. $1 each. I bought 50.
