...In older editions you had stuff to do with your gold and had less ability to rest-nova a cave of goblins down.
That's the issue. 5e created a problem but didn't teach the solution. 5e relied on your DM having the experience to create the solution.
Let's go to the 3E Rules, then. What exactly do you think was in the PHB and DMG that gave PCs something to do with their gold?
In all editions you can buy items - there were just fairly arbitrary specific prices in 4E tand earlier editions hat resulted in very powerful items being cheaper than much less powerful items. You could, for example, in 3E buy a ring that allows you to 100% of the time counterspell a specific spell (which you can change) for 4K gold ... or buy a pair of rings that can, essentially warding bond for 50K GP. You had certain items every PC was buying because tghey were undercosted ... but the DMG did specify a price and a lot of DMs didn't feel right ignoring it.
But what else did they have rules for in terms of spending money in the DMG and PHB for 3E that high level adventurers would utilize?
And what about 3E prevented the rest-nova? We lacked the short rest mechanic, the concentration mechanic, and metamagic was not restricted to sorcerers. As a result, you often saw higher level spellcasters casting a dozen spells before combat, multiple spells per round during combat, and burning up all their spells early and often. They also had
less spells per level until about 6th to 8th level. So what was giving them more endurance to avoid the rest-nova we see in 5E?
Or did we want to focus on 4E? Where in the 4E rules do you find things to do other than buy magic items? They had rituals which you could pay money to master (if you had the feature/feat). That was something for PCs to contribute to - but is it that different than hiring a spellcaster that can cast the spells in other editions?
4E also had the rest nova issue as EVERY PC had their strongest abilities recharge on a full rest. A common discussion in 4E, in many games, was, "When do we rest so that we can have our dailies for the big bad?" The entire edition was built to feel more like a video game than all the other editions ... and that mentality pushed people to treat it like a video game and less like a storytelling game. Thus, more "I think we need to go somewhere and camp because I just used my daily."
A lot of this "earlier editions had X" are a result of rose colored glasses. AD&D had a lot of interesting stuff that turned adventurers into Lords, but most of that was gone by 3E.
