Stability: Stablecoins are designed to be less volatile than traditional cryptocurrencies like Bitcoin or Ethereum. This stability could provide a more reliable medium of exchange and store of value, especially in economies with rapidly depreciating currencies.
stability and depreciation? A coin can be stable, but its value can still depreciate in some circumstances. If the stable coins are backed by a physical asset whose value is also bound to depreciate with an increase in the inflation rate, will it still save the economy? Most of those stable coins are backed by some fiat, like the USD, which means if the value of the USD depreciates, they will also be affected. Even volatile assets like Bitcoin are very important in the economy; they're a hedge against inflation as their value can greatly improve over a short or long period of time, but if inflation strikes, fiat drop in purchase power due to value depreciation.
Basically the logic is that stablecoin is pegged to dollars and dollar loses its value every year due to inflation. Which means that we are going to end up with something that will change the end result, you are not making a profit by holding it.
Not a lot of good passive income from them neither, some places give you like 2.5% or so return for keeping your USDT with them, but in most cases inflation is higher, and that means that you are not making any profit at all, you are losing it. The only acceptable reason to have it is that bitcoin may crash, and because of that you may end up getting a bigger result and should see some changes for sure. I think it's important to do something like that in order to have a greater return.