It all starts with open formats, open data and open apis. Unless this is somehow guaranteed by law for interaction with public entities, it's going to be hard for any FOSS projects or independent apps/developers.

Without that, we have a situation where almost every bank tries to shove their stupid android app in your face so they can more easily track you. They also force you to their authentication mechanisms, instead of using already working ones. There are no APIs that are usable, only if you have $$$$$. They'll just ignore you if you're a regular client and want to download your data automatically via a reasonable mechanism, etc.

If only banks can write apps and have closed API, they will