The right coach matters. I work well with mine, but I've had other experiences that were not very productive. It's a service, if you don't get value out of the first one it's worth trying someone else before you write the whole thing off.
My coach doesn't specialize in my technical field, but they have been working as a professional coach for a very long time. Career wise, they have seen lots of different scenarios that I have only experienced personally once or twice. There is value in that. I don't work with them to improve my technical skills (my coach is not a mentor!), I work with them to meet my professional development and career goals.
A coach keeps me accountable to my goals, they provide structure and feedback to my activities, and they are a forcing function for me to prioritize time for my own personal strategic planning.
Ideally, you can find a coach and/or a mentor who is in your industry, but I'd caution that coaching and mentoring are (two different) skills, and just because someone is a successful executive doesn't mean they are a good coach or mentor. Also, depending on the size of your field, you may not want to have these discussions with someone who is a professional peer, or even a potential supervisor.
Finally, you get out what you put in. The best coach in the world is only a facilitator. If you don't take your career seriously, and invest in yourself, they aren't going to give you a magic recipe for success.
Good luck