The only passive income opportunity in crypto market is, mining or staking. I don't think any other passive income opportunity exists here.
People who do not have a huge amount of money to set up a mining operation, can surely benefit from staking. With pool staking you also do not need to have a huge amount in a specific cryptocurrency. You can start with little and gradually increase your stakes.
If you know about any other passive income opportunity, let me know!
lending is also one good passive income opportunity but only limited with stablecoin since it eliminates risk of losing the value.
so many people are looping on lending platform to create higher profit but with higher risk, the defis like morpho and AAVE are having money circulation by huge amount.
so I think they are good investment as well.

but I guess it also falls under the same category as staking.