Though I completely agree with you, I want to say that excess money is a pretty normal thing in any community / city builder. In SimCity, Cities: Skylines, hell even Fallout 4, once you get to a larger size, your income is higher than you’d ever spend.
Using SimCity for a second, once your income is $25,000 per tick or higher, you’re basically in sandbox mode, placing whatever you want. Unless you’re an idiot and don’t keep your city balanced, it just causes your numbers to increase more.
That said, pulling from other city builds, normally when you’re to swimming in gold status, you use that to buy / build monuments or achievement level builds. Skylines has a space elevator, large hadron collider, fusion power plant, etc. Maybe the equivalent could be done?
I’d like this idea, depending on how it’s balanced. At the same time, how 1 'ling will just show up because we have enough gold and food bothers me now. The reason I say how it’s balanced is that this can hurt players in the beginning.
Use them to make the new gold flake so you can have ornate everything.