You can earn by holding bitcoin if its value increases.
Looking for other ways to earn from Bitcoin will lead you to fall for scams which takes your coins and offers you promises or staking rewards.
Referring to real services that serve bitcoin and earns bitcoin like Mixers for example
Mixers are independent services and they all have different ways they earn. You can create a service that helps Bitcoin holders like building a decentralized exchange and earn from it.
- Jay -