Yes, YFI is still alive and thriving. Contributors are actively contributing to the project, as evidenced by the activity on the Yearn.farm contribution page. YFI has a thriving community of developers and investors who are working together to make the project a success. YFI has seen a steady increase in value since its inception, and the team behind it is continually working to improve the platform and make it more attractive to users. YFI is a great example of a successful DeFi project that has been able to gain traction and grow in a short amount of time.
