I guess for a lot of jobs it's not actually that relevant who does it, as long as someone does. In fact, as a freelance contractor, I have the legal right to s

I guess for a lot of jobs it's not actually that relevant who does it, as long as someone does. In fact, as a freelance contractor, I have the legal right to send a replacement software developer if I'm not available. Of course I won't, because I know very well that in software development this is never going to work, but technically I'm a company with a contract to send someone to do the job, which means my responsibility is to send someone capable of doing it, not to do it myself. In practice of course it's always me, but contracts often specify explicitly that I could send a replacement, in order to make very clear to the tax service that I'm not an employee but a contractor.