Coinbase is offering “5.1% APY” for USD coins. That sounds too good to be true. What is the catch? What is the risk?

Coinbase keeps presenting me with this offer. If I just pull out like $100k from my bank’s savings account that has .25% interest and shove it in this offer, that means I’d be getting an additional $5,000 a year just by sitting on it. But obviously, that would be stupid. But I’d just like an understanding on why. Are USD coins something that can collapse? What is the deal here, how is this offer even possible? I know that to a lot of you the answer to this would be obvious, I just want a better understanding of it.