#9c1: Management is not a promotion.
Despite being fundamentally different fields, a career change from making (such as engineering, design, or product management) to managing is considered by many in the software industry to be a promotion. This notion is harmful to the individual, their team, and the organisation that promotes this idea.
A senior individual contributor who believes that career progression is only possible through a shift to management sacrifices what they're good at and what they enjoy. Their team suffers from an inexperienced — and perhaps disaffected — manager replacing a talented IC, while the organisation loses much of its frontline experience.
Some companies feed into this cycle by offering management promotions as a way to retain key talent, resulting in a management-heavy hierarchy with few experienced ICs.