In general, stakers refer to users who stake a certain asset to earn fees / rewards generated by the underlying platform. For example:
Balanced: BALN stakers earn trading fees (sICX, bnUSD, BALN) collected by the platform.
OMM: OMM stakers earn OMM rewards collected by the token economics.
Optimus: FIN stakers earn performance fees collected by all strategies.
How Optimus can help
For this strategy, users can deposit different assets to earn rewards on a compounding basis, since the receiveable rewards from staking usually include the token that can be staked further.