Progress was the first vehicle to transfer fuel from its tank into the Salyut 6 space station.
It continued with Salyut 7 and Mir.
But there were problems: corrosion of the fuel hoses. Because the station was meant for a long life, it better not get corroded by frequent fuel transfers.
One shuttle flight experimented with fuel transfer during a spacewalk. Kathryn Sullivan's EVA had such a task during her first flight.
But it never got very far, unfortunatelly.

There's a space station and still no space tug.

The thing is: Fuel transfer meant it had to be brought up from Earth one way or another. It's complicating the whole scheme and also adding risks!
So, perhaps, the thing to do is to build a rocket that doen't need fuel transfer operations but goes as directly as possible to its end destination, from the ground all the way to the other world.

Raoul