Exploitation of supply vs demand.
Say for a moment that you have hoarded hydrazine vouchers, and can effortlessly give somebody a trip to mars "Right now" in exchange for some service of dubious ethical quality. The vouchers would have to be "bearer bond" type transactables; The bearer of the voucher is entitled to the use or providence of that quantity of that product, upon presentation.
Unlimited manufacturing capability is not possible: There are finite resources of material and energy on the planet. As such, there is only so much capacity for production or delivery.
The ability to remit a full quantity now, in exchange for an imbalanced transaction (eg, "interest"), of some other commodity, would become the new means of accumulating "wealth."
EG, Random person wants to get to mars sometime in their lifetime. Tickets to mars are popular, because of AGW. (Thanks previous generations!) There is only so much rocket launch capacity the planet can actually handle; But there are other commodities that can be purchased more freely-- say, bags of flour or sugar. Logistically, what the "crafty, greedy wealth-baron" does, is look at the price-in-credits per commodity item voucher, and then offset his "prices" so that he gets a logical surplus. He says to the would-be expat-- "Hey, I see you want to leave the planet. Too bad for you the cost of hydrazine fuel is so high due to demand, that you cannot live long enough to collect enough vouchers. Thankfully for you, I have banked lots of other kinds of vouchers that I can exchange value of, to get you the supply of vouchers you will need... You just need to bring me X amount of these other, more easily purchased vouchers, and we can make a deal."
where X amount of that other voucher has a value in credits exceeding the costs of the hydrazine vouchers directly. By manipulating the barter transactions in this fashion, the greedy bastard quickly accrues more and more vouchers of various kinds, looking for interested parties seeking large transactions. If he can hoard ENOUGH of them that he can swing the supply/demand curve by threatening to remit his vouchers, he has the potential do control market credit pricing. All he has to do is have a means of storing the commodity. (EG, suppose the guy has enough "bag of flour" vouchers that he can appropriate the ENTIRE YEARLY output of flour production; He can do that, and cause an instant flour shortage. He remitted his durable vouchers first, and now people *HAVE* to exchange other vouchers for his flour in his warehouse, because he literally has it all. Again, he tips the balance and requires more "value" in his transaction than he expends; His power only grows.
(Essentially, he introduces himself as a middle-man. He says to one person seeking large quantities of say-- "bag of flour" vouchers, that he can do it, at an exchange rate of "one and a half" of another, identically priced voucher that is more available. He does this with one set of clients, asking for they hydrazine vouchers. He does it for another, with the bag of flour ones, etc.. etc... etc...-- He pays attention to what "Real market" demands are, and seeks to introduce himself as "The supply". The "bag of flour" vouchers supplied by the yearning expat, go to the breadmaker seeking more than his normally purchasable quantity of flour; with a surplus retained by the exchange baron, in exchange for hydrazine vouchers. The hydrazine vouchers go to the yearing expat, with a surplus retained by the baron. The value he adds to the transaction is in permitting a transfer of large sums of vouchers. He's a true capitalist.)
There is also the "Rent seeking" angle-- Storing actual product and moving it requires temporary storage while the product gets from factory to distributor. The greedy magnate says "you can store it here for X kind of vouchers."
You are just offsetting what gets hoarded.
The "hoarding of wealth" is really just "I have very high availability of resources; I can get anything I want, whenever I want."
This translates into the "attractiveness"/"distinction" metric, in that somebody that can get you anything you want is very desirable, compared to waiting. People are willing to do all kinds of unsavory things in exchange for that kind of service.