Good luck convincing Germans to surrender their data. I would be very surprised seeing this working out.

Also, you will get data from a very skewed demographic.

AFAIR there is an upcoming EU law which requires (at least some) transparency on how scores are evaluated, in expectation of algorithms making life changing decisions. We'll see how that's panning out.

EDIT: to clarify, I'd love to see this working out. But I never would give data of this kind to an unknown organization.