Their model works great.
It’s really about bypassing the existing power structure of the company. Competence of the work itself is a secondary objective. Most in-house initiatives can be slow rolled by management.
The fresh faced consultant with 2-3 steps to access the CEO neutralizes that. It seems grifty but is really exploiting bugs in corporate governance.
The current fad of firing the managers is a riff on this. Every jackass C-level is coming up with the novel idea of flattening.
This somehow implies that initiatives or strategies from consultants are somewhat successful. This is not the case in my experience.