i've used some in health space and one was completely overpriced for the services provided which left a bit of a bad taste but generally a lot of time you pay for the commitment and someone serving you things on a plate instead of needing to spend tons of mental effort and time figuring things on your own. that was the case for me in both cases, i think realistically for one i could've just been subscribed to the mailing list and got their "private" content out over time, it was more about the structure
i've also had a professional coach back in my corporate days which was also somewhat useful tho it was paid by the company so its hard to judge the price/performance
coaches can also be a great hack to get you to a goal much quicker if you can afford it
My wife is a certified professional coach. That's her side gig.
She always says it's as worth as you are willing to put the effort in changing your situation. Coaches will not and cannot solve your problems, they just bring them to your awareness, give you the tools, then it's up to you to decide what to do. Either way is fine.
Also, I know a friend who was diagnosed with cancer, had chemotherapy etc. She hired a health coach too...
Yes and worth it in case you're aiming to be professional in sports. For me it was all the way back as a junior. I don't know if you mean it in the context of sports or physical training or otherwise.