The problem is that centralization is required for general purpose use.
Nope, centralization is only required for integrating into the legacy financial system, which is only a temporary measure. What were you referring to specifically, as necessary centralization?
Mostly that no one wants to manage a wallet themselves, which will have the wallet providers functioning as banks. Tons of other services that will spring up around bitcoin will also provide centralization. It's just like the internet: sure it's "decentralized" but there are still a few key backbones and a few key regulating powers on it.