That's really high. How can they give fixed returns like that? What kind of business do they run? Are there a million users or what?
I feel safer with Compound, to be honest. The rate is not that good but at least I know how they get the interest.
Scams?
The rule of thumb is that a return is usually about 2% lower than they can lend it out for.
So a bank may give you interest of 0.5% on your deposits while lending the deposit out at 2.5%
If someone is giving you 12% on your deposit, they'd have to be lending it out at 14%. Which is impossible because no-one would borrow at those rates.
Which means this is a scam to entice the greedy to deposit their coins, and then vanish with them.