Y Combinator has already funded several Epic competitors in the EHR space including DrChrono, Medplum, and Akute Health. Always room for more. The requirements for an EHR that can work in any provider organization are so overwhelming that no startup could directly compete against Epic. But a startup could initially target a particular medical specialty or facility type that Epic doesn't support very well, then expand out from there.

https://www.ycombinator.com/companies/industry/healthcare-it

Epic is no longer a closed system. They now support a wide range of open standard APIs.

https://open.epic.com/