You will know how important stable coins are if you are new to crypto trading, I don't used stable coins and I don't have any reason to until I started trading on top exchanges like binance exchange, stable coins works very well just like having FIAT, the answer to your question is YES we need stable coins in crypto space because they are damn useful
Stable coins are very useful for everyone, not only for people who are new to crypto, but also for those who temporarily store assets before starting to trade on other tokens, so stable coins are a very good choice for everyone.