Staking rewards are charged the following fees:
DFI Staking:
15% of rewards.
MATIC, SOL, DOT & SUI Staking:
Up till 15% of rewards, depending on validator performance.
ETH Staking:
10% of rewards.
However, the returns and APY figures that are shown on Bake are net of all fees. It is the return that you are expected to get by staking at Bake.