As a boomer, I could have told them this years ago. Managers at the companies I worked for generally had the same technical responsibilities I, as a senior engineer, had but they also had to manage a group of people including job reviews, hiring, compensation, not to mention the sheer number of pointless meetings they had to attend. At the lowest level, there wasn't even a bump in pay. I refused to do this for years all because there really was no benefit to me and I didn't want the extra work load.
