It's kind of hilarious that you think this isn't political, because this whole thing is written purely upon assumptions that dwarven politics are exactly the same as the modern world's, as mentioned before. Saying this "isn't political" is the same as saying you aren't aware of how deeply ingrained your political assumptions really are that you cannot even recognize them as assumptions, but simple inviolable laws of the universe, instead.
The big problem with the old economy was found in three parts:
The first and ultimately most meaningful was that the economy was far too inflexible and did not react to the actual needs of dwarves. (In TV Tropes terms,
Karl Marx Hates Your Guts, amusingly enough.) All that changed was that things like simple stone crafts, whose value is still fixed and hyper-inflates based upon quality, are now property to be sold by merchant dwarves who can randomly set up shops. Dwarves can now buy the crafts they want, but most can't afford the price of the stupidly expensive all-masterwork crafts fortresses tend to put out under a player economy. Players need to either actively put less experienced dwarves in charge of making anything that needs to be purchased to keep prices down, or else just go for legendary on every dwarf, because legendaries are exempt from the economy. (And ultimately, the latter isn't that different from having no economy at all.)
The second was that there were no re-stacking rules. Nobody put things in bags, there were no rules for things like wheelbarrows yet, etc. Dwarves would drop coins on the floor in their room, quickly run out of floorspace, drop coins in the hallway outside their rooms, run out of floorspace in the hallway, and as coins broke down into smaller and smaller denominations, you'd have tens of thousands of individual coins carpeting the floor. Dwarves would only pick up coins when they wanted to buy something, meaning they'd run to the hallways near their rooms to start gathering coins before buying a new shirt, dump those coins at the store, wear the new clothes, then drop their old clothes on the floor in the hallway to gradually rot away.
The third was that the economy hypothetically should reward dwarves for taking more valuable jobs, yet it doesn't. Just like how there are static prices of goods, there are static prices for labors, and labors like hauling pay less than labors like stonecarving. They were paid something like 5 DBs to haul a boulder, no matter the distance, even if it took all day, while a stonecarver might sit in a workshop 5 steps from the stone stockpile. Distance traveled is by far the biggest determinant in the time it takes to complete any task as a dwarf becomes more skilled, so a hauler can never haul enough to pay their rent, while a craftsdwarf with even the most basic of efficient fortress layout is going to be rolling in dough. Likewise, dwarves in the current game do not select their jobs, they're assigned by the player, so this means that the player has to micromanage who gets certain jobs in order to see each dwarf has enough money to eat, or else they're creating a permanent underclass of "unskilled labor" haulers that can't afford to eat, while the permanent workers all rocket up to legendary and never having money worries again.
Now, all of these are pretty blatantly the result of a lot of placeholders in the game, so complaining that a feature that was taken out because the supporting features needed to make it make sense weren't there shouldn't be put back in because you aren't even considering that the supporting features might ever be put in is kind of ignoring the core of the issue.
If you want to talk solutions to some of these problems, I have a rather old suggestion thread,
Class Warfare, that discusses the topic of making the economy make sense to bring increasing complexity to dwarven society as a fortress matures.
However, to cut the whole thread I wrote short and go to the specific topic of how the economics of a medieval community works, you should try reading someone like David Graeber, rather than economics philosophers talking about modern theory.
For example, nobody in the medieval world tended to use coin money when trading with their own town. There wasn't nearly enough metal in the ancient world to support a physical cash currency system. (And we use fiat currency in the modern day because even with modern mining techniques, there STILL isn't enough metal in the world to mint into coins.) At most, they would use tally sticks to cover large debts, but most intra-town transactions worked on credit or the honor system. No, not the one where you are honor to put a quarter in the box for your bagel, the one where it's fine to ask your neighbor for some eggs if he's got some spare, but it's an affront to your honor to let a debt go unpaid for too long. (And hey, dwarves and honor are a good combo!) Since this is a computer, and we have exact change, this will be more exact than actual notions of honor, but you could easily just have an intangible honor system where doing work for the fortress builds up an intangible stockpile of honor that can be traded for goods and services. Everybody just mentally keeps track of who owes who what, and the exact prices weren't really kept track of, but it's vidya gaems, so it can be super precise because computers don't fudge well. The members of the same fortress don't need currency to trade because it's presumed that everyone is going to eventually balance out all their debts with one another as everyone is mutually interdependent upon one another, and if they don't match up exactly, nobody should complain too much because they're all your friends and family, so what's not paying back one borrowed egg over a lifetime, anyway?
Coins are only necessary when trading with someone to whom a long-term debt cannot be expected to be balanced. That basically means traveling merchants (which had a really negative reputation throughout history specifically because they were the one class of people that didn't share this presumption of repaying all debts, and cared about sinful things like
money like only nobles, merchants, and criminals do), plus travelers that visit your tavern (who were also historically viewed with great deals of suspicion). Coins are almost exclusively the purview of merchants and soldiers. (In fact, most precious metal would historically be turned into things like statues of the Buddha or crucifixes during times of peace as the temples - the only institution that does not spend what they tax, and hence are a leech on the economy - naturally consumed all the coinage in tithes, only to have those statues melted down and turned back into coins during times of war. You can't distribute a statue, but melting a statue into coins allows divvying up the loot for all the soldiers you promised would get rich following you into war. Of course, it's bad form to melt statues from your own religion, so let's go sack another religion's temples to pay for our army. Gee, that leads to the easiest way to pay debts to be to launch a holy war, doesn't it? Even nobles ran entirely on ledgers of debts, as their actual material income in taxes was generally agricultural goods paid in kind. Honor-debt-"currency" is inherently personal and carries one's reputation with it, while coins are inherently self-laundering money. Nobody knows how you got it, so the more coins are in circulation, the easier it is to be a criminal, and hence the more violent and crime-ridden the time period.)
No matter how you look at it, using coins for intra-fortress trading was wrong from top to bottom both from a gameplay and historical standpoint, anyway, so there's no reason to bring that part of the game back at all.
(Edited to correct for mistaking "inter-" for "intra-")