My sister is the hermit crab expert in my family, I mostly only have second-hand knowledge through her

But for starters it is really damn hard to breed hermit crabs in captivity, so basically every one you've ever seen in the pet trade is probably wild-caught.

They also have really specific habitat needs, high humidity, warm temperatures, access to fresh and salt water, deep substrate that they can dig and burrow in, vertical areas they can climb on, I think you should ideally have like 10 gallons of space per crab, and basically no hermit crab kit out there actually meets these needs.

And while a lot of people think of them as sort of throwaway pets that will only live a few months, with proper care they can actually live years, even decades.