Consider stablecoins as fiat currency on the blockchain the only main benefits of stablecoins is having the ability to take advantage of fiat currency (convert your coins to fiat to avoid volatility) while still operating on the blockchain the rest benefits are just bonuses and wasn't the main intention of the creation of stablecoins in the first place.

Example USDC (Stablecoins) is USD on blockchain. Meaning with stablecoins you can use USD on the blockchain.