I presume you mean the "groups" utility, in which you can create groups of your own naming.
The main benefit is so the other, related hubs will show up at the bottom of the page under the, "Discover More Hubs" section. If you don't have your own in groups, you may or may not have any other of your own hubs shown there. If you have them organized into groups, then there is a good chance that at least one or two will show, along with the selections from other Hubbers.
This is a traffic-driving tool, and can help you gain additional views to your other Hubs. I hope that helped, and is what you meant. Cheers!