This point is very cool because copy writing is one of the numerous writing opportunities for freelancers. It can be chosen as a means of earning cool money by helping people in business to copywrite their brand advertisement. So a skill acquisition in writing is not a waste.Well, this will depend on what you really are good at. But i usually advise freelancers to have writing skills. Irrespective of their main skills. Copywriting skills will be necessary in your own business, in pitching your gigs, in your day to day life even in simple conversation. Thus, i would say, one must at least have writing skills in his arsenal.