But my power points at home are protected by breakers/fuses why do i need an ampfibian again?

Individual 10A power outlets are rated at 10A, but the breaker/fuse connected to the outlet is rated at 20A. This is because there are always several outlets connected to one fuse/breaker (this is called a circuit). It is therefore possible to draw 20A through a single power outlet without triggering a breaker/fuse.