My villager doesn't want to take the job. Why is that?

I play survival minecraft and need a farmer. He is currently unemployed, but does not want to take up his job as a farmer, even though the composter is right next to him. As I said, he's unemployed and I don't know why.

He could be no good. They can't take a job.

They are mostly dressed in green somehow or something.

Should I just kill him and use someone else?

Can you do. If you have others.

Yes, the uselessness is useless and just annoying.