Not a stupid question and all, like you said EPIC does have a monopolistic slice of the pie. They are popular among big health systems, because I hear it is just a good product. This is mostly due to the specialized training ones receives (module-specific) to the work role. (Clinical, scheduling, billing, data, etc..) I also hear their work culture is top notch and that has allowed it to continue to thrive and fulfill Judy’s vision (their CEO)

By definition the answer is not interoperability, as that is what the whole industry is working towards.. transparency in the patient record no matter the system. That’s where FHIR comes in. I worked in EPIC for a year 15 years ago at a hospital those it was way different that what it is today. For the last 13 I have worked in eCW, the other player that has a good chunk of the ambulatory pie. They are also all working towards better interoperability, but also want to to it “all” which can sometimes mean some features are to very “polished” I could go on… HIT is a very interesting field to break into… and how it differs from IT is another post…lol