You will need a refresh button as long as there are bugs in software - in particular, as long as there can be a bug in your UI code or your operating system's UI handling code.

I feel the difference between a programmer/power user and a regular user, and something that we need to start explaining to regular users, is that UI is not the true state of things. What you see is not what is really there. What you see is a representation, that is usually manipulated incrementally. A refresh is a request to rebuild the representation anew, from the true state of things.