I previously worked for a startup that did denormalization of healthcare data for the ostensible purpose of data "freedom" and interoperability, with a future f

I previously worked for a startup that did denormalization of healthcare data for the ostensible purpose of data "freedom" and interoperability, with a future focus on ML funsies. All the issues we had (besides ones we created) were around the healthcare providers fear of pissing off EPIC, Cerner, Meditech, Allscripts etc. They didn't like their EMRs---in fact they often hated them. The fact is though that there really is no viable alternative, and the data is kept behind a gate and essentially "owned" by the EMR. FHIR was supposed to solve the interoperability bit, but all the EMRs would still own the data, and their lawyers aren't keen to share.