Earlier quoted context omitted.
how about getting a higher interest on your savings account using defi on your usdc? Isn't this a real world use case?
That's as much of a use case as "get rich from dogecoin". Both of them are based on speculation. The "high interest" is just a derivative that shapes the speculation a certain way. Underlying it is still people speculating on cryptocurrency. It's different from a conventional bank account, because there the returns are (theoretically) coming from the bank loaning it to entrepreneurs to buy factory and farming equipme…
You could however be morally against earning interest through others speculating. In that case you could still earn better interest by just by being USDC-sUSD LP on curve.fi.