Clients are looking for collaborators, not adversaries, not know-it-alls.
Copywriters have hard and soft skills, hard skills in the sense of being a good writer, being curious, a stellar researcher, and a grammar extraordinaire. A writer also possesses soft skills such as attitude, flexibility, motivation, methods, or demeanor. It would be better if the freelancer used the term “we” more than “I.” Clients do the hiring. It’s their company, their goals, and they pay the bills. Have a team attitude. Don’t be controlling.
I'm also posting in Community Discussions: Freelancers. See you over there.