For example, Eco is a non-crypto app that seeks to compete with CashApp, Venmo, and Apple Pay.
Although Eco is a fully non-crypto app, it is built on top of crypto rails.
Eco offers its users greater savings rates than traditional banks by using crypto to literally cut out the middlemen.
As well, Eco accounts are not FDIC insured-- but, I think that's a temporary downside of the current regulatory landscape. It seems like there's no reason why Eco accounts couldn't be FDIC insured in the future. Happily, the benefit of cutting out the middlemen is forever.
The Eco team has written a lot about their experience disintermediating banks. I recommend their blog https://www.eco.com/blog
Do you have any example of a use case with traction that serves a need not created by the existence of the cryptocurrency market itself?