Maybe a factor of why this happens is the expectation for senior engineers and higher to do less hands-on work and more management and planning work, which lead

Maybe a factor of why this happens is the expectation for senior engineers and higher to do less hands-on work and more management and planning work, which leads to an overall degradation of technical skills because engineers don't specialize in their domain for their entire career. In other words, the tech skill shortage is self-inflicted with the industry pushing for engineers to add "business value" as the number one priority instead of focusing on mastering their technical skills throughout their entire career.