so far I don't think there's any safe place to stake BTC on-chain, most of the chain that allow stake BTC actually wrap your bitcoin and exchange it for a token pegged with the bitcoin, be careful because this add layer of risk, the coin can depeg, not anyone have good intention. maybe you can stake it in cex, they usually do have some staking program where you can stake BTC, but it's again at the end of the day, custodial staking.

as for ETH, you got plenty of options, ETH nowaday mainly being used for staking due to the recent appearance of staking protocols, try provide liquid in dex, lending, and liquid staking, all of them give you APY, be sure to understand the basic and don't fall for scam project though.