This grows like a cancer: it starts from the bottom of the pool with people with no much skills, but looking for promotions while people with skills are looking for work results. In some very large companies I worked in (or with), techies focus on work while less competent people become managers; techies regard managers initially as admins that do work techies don't want to, but then the managers take over the organization and make it rot. This is initially far from senior leadership's sight, when it becomes visible it means most of the organization is already affected and it is too late. In most cases HR is helping with this because HR is completely disconnected and not understanding techies and the power dynamics ("those geeks nobody understands") and side with the bureaucrats because HR is also a form of bureaucracy (you don't get in HR is you are a brilliant STEM graduate).
I work in one of those organizations (US legal requirements make it a nightmare)... I even have stock incentives, and I couldn't care less.
I don't have empirical evidence for it, but I can take a stab at a rational explanation.
The second group faces no opposition in their pursuit for control of the organization and its processes.
At best, members of that group will fight among themselves, but certainly won't find resistance from the first group.
Control over various parts of the organization is therefore slowly given to one or more members of the second group.