One of my most frequent freelance clients was a web developer who farmed some modules out to me to be implemented. From what I could tell, he used FTP for deploying changes, and did not use any kind of version control. I kept him on as a client because I needed the work, but this lack of proper tooling caused numerous headaches. In retrospect, it probably would have benefitted both of us to condition any work for him on his adopting source control for that project.