Staking is by far the safest way to earn that huge amount of return, but when I mean safest, it doesn't mean that there isn't any risk on it anymore because any investment has risk, and we should know that. What I'm trying to say is that, staking can give you that return (depending on the coin of course), but there's a risk still to it. Another one I guess is providing liquidity in DeFi's, but no one is talking about it anymore thus, I don't even know if many are still using it right now.

As for banks giving 5%, I guess you are referring to digital banks who are offering that amount when you store money in their digital mobile app. Traditional banks aren't giving that huge, and the highest I think that they can give is at least 1% which is pure sh*t knowing how high inflation is right now.

Crypto exchanges giving up to 15%? You can try it, but the risk is high knowing that exchanges are prone to hackings. Don't recommend though.