Well, we first need to chill out and see how things progress. Right now, LG is nothing more than a touted World Wonder of modern age, but nothing more.

At the time of its construction, ISS was supposed to be a hub for further space explorations, where Shuttles would bring in components for Mars missions that would refuel the ISS before heading off to the Red Planet and stuff like that. Now, it barely serves 10% of the purposes originally touted.

But to explain a bit more the plan for LG.

LG is part of a whole system of lunar transportation. Unlike current and previous means of reaching the Moon, which meant the need to have a spacecraft going back and forth from Earth to Moon, LG project envisions LG as a node in a transport network, where supply ships will create a stockpile of materials on the space station and then there will be another fleet of space ships dedicated to going from LG to the Moon and Back. In theory, this is a bit more efficient than simply repeating the Moonshots because you can jampack a lot of unmanned rockets with supplies for LG and send them back to Earth, optimizing fuel consumption. Bleeding delta-V is not a problem as big as you make it to be. If you want to land something on the Moon, you would still need to bleed a huge portion of your fuel reserve in order to reduce your relative speed. Instead of bleeding it fully to land on the moon, you bleed it partially to dock with the space station. And then you bleed it again using a different space craft optimized for landing. Again, the efficiency bonus comes from the fact that you can send in lots of large supply ships to the space stations which you do not need to worry about getting off the Moon (which would require extra equipment and more fuel). The landings would be done by more simpler space craft, with streamlined equipment, which would lack stuff like thermal shielding for getting back to Earth (which would reduce their mass and fuel consumption)