I have had to work with willfully incompetent people who could not be fired. I will not do it again. I have been contracting the past decade and it lets me fire

I have had to work with willfully incompetent people who could not be fired. I will not do it again. I have been contracting the past decade and it lets me fire the company when I am done. Neither nor the company have any illusions this is anything other than business relationship: I make code I get money, done. I don't want to fail because I need to drag dead weight around.