In some way, yes it is I think. A coin like BTC,eth,ltc is not very stable like usdt,dai,usdc etc. so if a coin like usdt,dai was not there then it could be very risky for us to keep a coin like btc,eth in hand when the market volatility is very high. And also a stable coin backed by some assets. Like USDT was backed by USD. That's why the price of USDT stays stable in any condition.