You haven't addressed the point that jeremylee made about the SMART on FHIR platform now available in those EMRs. It's not a complete solution but it works today and people are building real applications on it. Take a look at the demos from the latest HL7 FHIR Applications Roundtable.
https://www.hl7.org/events/fhirapps.cfm
Here's an interesting episode of the weeds podcast that gives some context by exploring why the fax machine is still so prevalent in US healthcare.
https://player.fm/series/voxs-the-weeds/fax-reform-bonus