This question seems very group dependent. If your group wants cinematic discrete adventures, you don't need much gold.
In the ancient past of 1e, there were tons of things to spend money on, a mix of carrots and sticks.
Some sticks included: 1) mandatory upkeep spending (100 gp/level); 2) level training (1500 gp/level time play rank 1-4); 3) taxation and tolls. I imagine these would be super popular today /s. Strongholds were the big carrots, which gave access to followers and, well, a frickin' stronghold. But ships are nearly as good and perhaps even better for adventuring. I allow ships to be used like strongholds and attract followers. And there was also magic research, time-consuming but a good way to avoid magic shops (which I also don't like).
A simple way to make gold more useful is to make it clear that the party needs to spend money to get what they want. If you want an audience with the archduchess, hire a good tailor and bring a gift. 1e had very intricate rules about hiring and using sages, fonts on knowledge. The implication was clear that if you want to know something, there is some (large) amount of money that will get you that information. In a world where encumbrance mattered, you hired bearers. And so on.
Basically, if you want money to matter, have it matter!