You're looking at it too holistically. Rarely does a tech come and entirely replace something outright (despite what the AI hype bros have been saying)

There will be 50 or 100 companies who know the space working on a single thing the nurse does. My suspicion is that nurses do a lot of book keeping and state recording, that is likely what will go first. There might eventually still be someone administering a drug but fewer people doing data entry.

Still health care is notoriously slow and penny pinching so I suspect it will be a while and the only entrants will be big companies who know how to navigate large government or private organizations.