I liked their ideas around direction given vs. direction required. I liked their distrust of the notion of "cultural fit". I liked that they identified leadership and connectedness as distinct skills, and that a senior developer has both technical skills and at least one of the other two (leadership or connectedness).
But true technical expertise requires the ability to make holistic, contextual decisions. That kind of stuff takes experience shipping multiple products, full-stack exposure to at least one or two mature software stacks, and awareness of the historical context of how technology has changed. That is, it's not so much about "years of experience" as it is "diversity and quality of experiences".