In our daily life, we don’t care much about the value of fiat money (in most countries). Why? Because many places we make a daily trade - like buy a burger - receive the fiat money in a fixed value. Big Mac is 4,500 KRW today, and tomorrow will be too (though they may raise the price someday). It doesn’t change to 4,483 KRW or 4,508 KRW tomorrow. So we can expect our expenditure horizon, within the foreseeable future.
What if our (expected) daily expenditure is volatile? People will be worried, even the volatility is small. The fact, that the value of money is volatile, itself makes people worry.
So, what if a big crypto platform like Uniswap, Aave, or Compound issues a stable coin, and treats the coin at a stable value? The user of the platform will use the stable coin, if it is a lending platform, as it is free from the liquidation risk induced by the price volatility, or if it is an exchange, as it is a safe “store-of-value” - until the platform is popular. That means, only the big platform can do this.
These days we see a lot of “unstable” stable coins like algorithmic ones and backed-but-market-price-is-volatile ones. The stable coin that is usable in the platform will be a new moat to the big crypto platforms.