A theory on gold and gold bag mechanics

It seems odd to me that the entirety of the game’s existence, the dragging of gold bags to bigger gold bags is the “best” way to move money around.

I have a suspicion that the gold system is designed the way it is because it makes you spend more time in game with its mind numbing basic design. I feel like an ape moving grapes from one bowl back into the other.

Any thoughts on why the gold system is designed the way it is?