Yep if the coin fails or exit scams, you also lose everything;

1. All the stable coins you see are not like Bitcoin, they are high centralized and very prone to security attacks and Government seizures.
2. Defi platforms are high centralized and also prone to hacks

Basically, you are going to double the risk of losing your money by using a stablecoin then a Defi platform to keep your stablecoin for just less than 10% APY

Solution:
Just buy Bitcoin and HODL. You get way too many gains than those risky defi platforms