Why there’s only one MFi battery pack on the market?

I’m looking into purchasing a good, fast wireless charging battery pack for the iPhone, but I could only find one battery pack that can provide the full 15W wireless charging capacity, that’s the OtterBox Multi-Mount Power Bank with MagSafe MFi approved (15W).

but that comes with an extra stand, and a car mount… like, yes, those are cool, but it makes the product expensive, when I really just wanted the battery pack.

I hope more companies, or OtterBox can release other models of battery packs that are MFi approved, and can charge the iPhone at the full 15W power.