We already have banks yeah, but we don't want them as centralised as they are. If we want to offer a viable alternative, it's smart to provide what the rest of the world provides, but better, rather than a hollowed out version of it that might not suit every lifestyle.
The HBD savings was never meant to be 20% forever, and will likely drop eventually to rates lower than my own country's current inflation rate. I would prefer the option to counter-act that inflation by holding it longer term, while also not being beholden to the whims of centralised banks who shut down out bank accounts arbitrarily.
I guess I don't really deal with any other 2nd layer coins and tokens so perhaps it seems overwhelming for the people who do, but for me it seems perfectly straight forward on the face of it.