Management is very prone to fads. The current fad is that middle management is useless. Tomorrow, they'll discover the idea that organizations can have employees "working hard" on things that no one cares about, and that someone actually needs to work on focusing that effort.
Of course, the truth is you can have too many middle managers or too few (it really was bad that in 2017, the biggest achievement was "growing headcount"). But fads have a tendency to overcorrect.
I'm not sure it's so much a fad rather than recognition that AI-assisted engineering calls for flatter orgs. Also "growing headcount" as management yardstick persisted way longer than 2017 - all the way into 2022 until the rates shot up.
Of course, the truth is you can have too many middle managers or too few (it really was bad that in 2017, the biggest achievement was "growing headcount"). But fads have a tendency to overcorrect.