Reflecting on the original question: I think 5e games are pretty likely to not have any real use for gold, for a few reasons:
You might be able buy magic items, but you might not, and both of those ways of playing make a bunch of sense to me. 5e goes out of it's way to make magic items (or at least a specific type or amount of them) optional, and removing the ability to buy them is an added benefit for a lot of people. However, once you do this, the only game-influencing expenses are mundane gear like torches, and the amount of gold in an average loot pile (if you follow published guidelines) makes those trivial pretty fast. So if you're not running magic shops or OSR-style detailed encumbrance, gold isn't directly affecting the game mechanics. And those types of play aren't always present.
And the non-mechanical uses for gold (downtime, shopping for the roleplay value) require a type of game that also isn't always present. Some adventures don't allow for downtime, either by the nature of the threat or location, and some do. Some players are interested in investing their gold, and some just aren't.
But the DMG guidance is to give out quite a bit of gold - more than you need for mundane gear, especially if you're not using a lot of it. Between these, it's pretty common to end up in a game where after a few level you literally have more gold than you can ever spend.
I'm not sure this quite rises to the level of a problem - but it's not an ideal way to write the books.