Expanding job roles is primarily a chance to move from boring routine work to something more interesting without taking a pay cut, so yeah, there is career growth. But for patients it could mean that a nurse or paramedic with expanded authority will be able to take on more functions that used to fall only on doctors - diagnostics, prescribing basic treatment, running consultations. In other words, shorter queues, faster appointments, people don't have to run around between offices looking for a doctor.
I saw this at a clinic: a nurse used to just give injections and take blood samples, but now can do an initial examination herself and prescribe some basic treatment for simple cases - colds, scrapes, change bandages. The doctor then handles the more complex cases. But it only works if the nurse is actually well trained and doesn't start "treating" everything under the sun. Depends on where they implement this system.