Medium of exchange + store of value.
Without a mechanism to reduce volatility, an unstable cryptocurrency will not be able to serve that purpose.
Finally, somebody who gets it.
For a token to be accepted as payment, it
has to be stable. Nobody wants to receive a token which could be worth 10% less the next day.
A stable token is only as stable as the asset that backs it. That's why "stablecoins" backed by gold, other cryptocurrencies, energy and the like will never pass muster. The collateral itself is not stable and therefore cannot provide stability to its underlying token.
Even stablecoins backed by fiat, such as the USD, can't lay claim to being a store of value. Fiat currencies by design lose value over time, so any coin or token pegged to fiat will lose value due to this built-in inflation.
The answer lies not in backing a token with fiat, but with something which is similar, but superior. That "something" is interest bearing financial instruments such as U.S. Treasuries. This can make the token gradually rise in value, negating the detrimental effects of inflation.
That will give the token the ability to serve as a true store of value in addition to a stable medium of exchange.
Further info:
https://www.startengine.com/monetran-llc