Hallo Abhishek,

sorry for late response. Yes, you are right. Star point routing is always the best, but hardly to achieve in real big applications. Think of a mixing console for a recording studio. There are hundreds of ground connections to be done, internally, and it's totally impossible to route a cable from each point to central ground point. In these situations effective ground routing is the task for the real expert...
If realization of only one star point is hard to achieve, technique of local starpoints is used.
Another disadvantage of star point routing in high speed systems, like digital boards, is, that inductivity of these many ground connections would not allow any correct functioning of application. But how to decrease inductivity of ground connections, while at the same time achieving star point routing? Simply by using a solid ground plane.
By the way, for me, a ground plane is not a 'plane', but a large area star 'point'.

Bye,
Kai