I think this idea applies to diet, fitness, career coaching, basically all forms of self improvement (getting career advice from someone who became a career coach is especially ironic).

I think there are benefits for some people in having a system, or having external motivation. My wife goes to a personal trainer for example, which I'd reflexively say is unnecessary but I've seen how it makes her stay focused on what she's doing, even if it's mostly just a list that you could get on the internet. It's the same thing for writing advice. It will work for some, be pointless for others, and draw in a wider group than it actually works for because some people are expecting a silver bullet.

That said, there are definitely worse things to try

Just to add, I like to take notes, but only scribbles for the sake of noting the key points. I rarely if ever look back at them, and when I do they are mostly illegible, but I find the act of noting helps me remember. It was the same in university.