All the protocols that you have mentioned other than MPLS helps in transporting other network layer protocols or to build VPNs either at Layer3 or Layer2. MPLS is primarily used in IP networks and attaches a label to the IP packets which is used for forwarding by all the intermediate routers. The advantage of MPLS over others is number of applications possible using MPLS like VPNs, Traffic Engineering, transporting Frame-relay or ATM over an IP network etc.all of which is not possible with the other protocols that you have mentioned.
The MPLS devices use the same forwarding plane for all applications to forward packets by looking at the attached labels. The meaning of the label and how they are distributed between the various devices is what separates one application from the other which is called as the control plane. So it makes building new applications easier by building a new control plane and retaining the same forwarding plane.
