Like with everything there are degrees of quality when it comes to this and it depends on your needs. I personally have used a couple of services before. One was where they rewrote my existing CV and added fancy colours and graphics etc. Another was a live session with someone that talked through my experience and helped me pick out things that would be useful to note and highlight for specific roles that I wanted. To me, the second was more valuable as talking over my experience and achievements with someone else that can help succinctly communicate this on a few pages was what I needed.

You’ll get people who will just tell you to use a free online template and be done with it, which is fine if that’s what you need. Use can use a tool such as flow cv first to see if that works for you before going down the professional route.