You can get fiat on Nexo. It's not decentralized but if you are already using it.

20% is hard to beat, you could split your money in 2 and let them both auto compound for 6 months and then see which one earns you the most and then you'll be more confident to put all your funds in 1 over the other. Nexo is very safe, i've been using it for over 2 years and never had a problem. HBD is an unstable stable token but 20% per year should amend for it. It's honestly a toss up