I have had 1:1 coaching with Dirtschool. I found it a proper eye opener. I had been riding the same sheep lines and stiff body language for years not knowing why I was stalling, falling and not knowing how to go faster where I wanted to.
Post coaching I have been able to think through the processes of my riding and why things work and why things don’t. It was a very positive experience for me. I still get lazy and make mistakes etc but I can now see what quite a few of them are and try to avoid making them in future.
I used to watch videos and think I was doing the same sorts of things as people I was watching. I would say I was an OK rider when actually I was very poor. Coaching opened my eyes to how much body language you can use to increase flow and stability on the trail. It also opened my eyes to many different lines I would not usually consider and what the benefits may be for taking them. Made riding even more fun.
The coaching was a couple of years ago but I am still working on some of the things shown to me. It planted a seed.
I think some people can find their way to their own solutions easier than others. If you have strongly set bad habits a coach should be able to show you them and teach the benefits of trying other/better approaches.
Coaching is proven in so many areas that it seems odd to dismiss it as not being able to offer benefits.