We are only limited, not by the instruments, but by our imagination.
Don't know about that, I can imagine quite a few things the Tyros 4 doesn't have that I and millions of other people use every day around the world.
The Tyros doesn't even have a proper Sequencer, let alone a sampler, full midi implementation, or even a sound engine that can access all it's own functions.
I'm almost tempted to start throwing around the terms Home Arranger VS Pro Arranger and comparing.