opamp as buffered output?

I have been looking at different methods to buffer a uC output pin.

The most common seems to be to use a buffer ic or transistor in common collector mode. The problem with either of those methods is that if they are powered by 5V then the output will be less than 5V.

I wondered about using an opamp in voltage follower configuration instead. Any issues with this? The uC pin is not outputting clock rates (just slow gate on/off signals).

What's wrong with an NPN or a logic-level NFETas a common-emitter (grounded)? It inverts the port signal, but you can just invert the data bit in software to compensate.

Most opamps dont even source or sink as much current as the port pin does.