> would even guess that for the vast majority of successful careers, competency and luck played a much bigger role than being deliberate about it.

I think this is true. I had a while where my career was doing really well constant steps up, I was learning, getting promoted, was working on great projects and problems that were engaging and led to easy promotions. Then I got a new manager and it was downhill. Then I got a new job and the problems are insignificant and there's no room for growth of any kind. If my latest job was earlier in my career my career would be very different.