Just as not everyone is capable of teaching, not everyone is able to be taught. If you are going to have a coach, you need to be able and willing to listen to what is said, and to apply it. At the same time, I don't think you can just blindly do what you are told, because you will always have insights not available to your coach. It isn't all in the data files. There needs to be effective communication - a good dialog. An athlete should be willing and able to challenge assignments and approaches, but then of course follow assignments as precisely as possible. Not everyone does that! And, if you don't enjoy the structure, if you aren't willing to ride alone instead of doing the group ride, etc. etc. then, well... it isn't just a question of whether you should have a coach, it's a question of your approach to the sport. If you want to do your best, you are going to have the structure, and sacrifice some things you enjoy, whether you have a coach or not. Doing so makes some folks happy - others not so much.

Do you have to ride/race together all the time? That would certainly be ideal, especially when it comes to things like cornering, but I don't consider it mandatory so long as you communicate well. I'm capable of knowing when I mess up, and how I messed up. Ditto for when I get it right. I try to not repeat mistakes, but I often do, because we all have tendencies, strengths and weaknesses. Your coach obviously needs to know those.

I hired a coach right when I decided to start racing, about 18 months ago, after having only been riding for about a year. She helped me make rapid progress in fitness, and also in basic handling skills. I've come a long way. But now I need to learn how to win Masters races, and so I'm working with someone (Ex) who knows exactly that, and also how to teach that. I'm now focused on the specific skills and power profile that will win races, rather than on more generalized development. I'm also practicing new cornering techniques and using new positioning. I bought a TT bike and am building strength in the TT position, which will carry over to breakaways in crit's and RR's. Two very different coaching experiences. Both, for me, invaluable. I would have been floundering on my own, and would not have progressed nearly as quickly. When it comes to investing in the sport: Coaching > Power Meter > Other Stuff