Until you reach a few problematic points.
Where are you keeping your loot? Do you mean to tell me you are schlepping around a couple backpacks full of coins everywhere you go, O Homeless Wandering Killer? Do you take it into the dungeon with you, and if so, how do you plan to carry out more?
Second, they wreck the local economy. “Nice village you have here. I’ll take it. No no, I mean pay for it! Your mayor’s house will be a good starting point I can build up to my mansion… For when I retire.”
Third, they might get a little blase and lazy. “And for this you’ll pay us what? So, what does the dragon probably have? Eh, I have that much gold in the other room, in the museum for racehorse hats…”
I have some solutions I’ve used in my games, to drain loot from characters without inspiring a chorus of complaint. Let’s use a principle based approach.
1. The benefits of civilization and religion come at the expense of taxes and tithes. (The great thing here is, when they are doing a favor for the church or state, then offer “duty free” treasure and watch their eyes light up.)
2. Your standard of living has expenses that can be lumped together into tiers of expense, because nobody at my game table wants to go through coin by coin. (The great thing here is letting them really live it up–that makes their characters feel cool even if they aren’t stabbing things in the face at the moment. Best example ever–Lord Bowler, from Briscoe County, Jr.; and his butler, and his crystal.)
3. Gold can unlock goodwill, training, and favors with powerful people if properly applied.
4. It kind of sucks to be homeless. (When the characters have neighbors, or become rulers, or whatever, they get built into the world, and the world gets built into them, and loot for personal gain fades compared to loot for the community’s sake.)
Using these four basic principles, characters can quickly be reduced to the amount of coin they can carry or plan to lock in their basement.
Here is a disconnect between what players and characters need, and what they want. They need to stay a little bit hungry, and to have their game experience enriched by their wealth. They want to have their cake and eat it too. In other words, they should have goods and services that rack up impressive bills as signs their adventuring careers are taking off, but they want to have those goods and services and keep their loot.
There are models that can offset some of that anxiety without ending up with a lot of book keeping.
Conan. Each story, he began in a different life circumstance; a novice thief, a pirate captain, a fugitive, a mercenary, a king, a survivor of a crushed army, chief of a tribe. It was not about the loot he carried, or the station he aspired to hold, but instead about how his innate vitality and experiences gave him the edge where others fell. That is a “loot” that comes from a combination of the character sheet, the player’s ingenuity, and the DM’s willingness to showcase and acknowledge the character’s strengths. Then blow it all on wine, women, and song.
Buried and Built. Early on, a character buried treasure in the woods, and made a map. The efforts of the party led to increased stability and peace, which led to increased building of homes. The character was annoyed to find that a peasant family built a cottage over their buried treasure! But by that point, they were wealthy enough to be philanthropic; they dropped the family a note with the treasure map, and enjoyed the flabbergasted delight of the peasants who became fabulously wealthy with what to the character was a meager score, against current standards. In other words, the loot is, in the long run, possibly less valuable than the peace and stability the character group’s efforts inspired. Also, this tale is a reminder that player characters should make stashes and caches, but not always be able to retrieve those goodies without complication later. How much fun is it to adventure for the same treasure twice!?
Feeling Superior. Let them see others who rely on their magic stuff, who are rendered impotent by the loss of their equipment. Let them see Iron Man stripped to become Tony Stark. Offer them ways to build their careers on chutzpah and more common gear, then show the bully-like helplessness of NPCs who rely on their magic gear and cry like little girls when forced back on their own resources. Or, if that is your group, reverse it; perhaps inspire them with others who make do with less.