These items are not marketed as baby hamster products, merely hamster products. In addition pet stores don't actually stock anything bigger. I had to go on the Internet to find a wheel that wouldn't cripple her. I can understand if the pet shops offered both, but they don't.
Maybe it's a marketing ploy to have us believe hamsters stay tiny, but they don't so squeezing them into tiny cages where none of the accessories fit is cruelly undesirable. So if you, like me, are contemplating your first hamster, try looking on somewhere like Zooplus instead of being duped into buying one of those tiny (and temporary) hamster torture chambers on offer locally.