It appears that they key skill is coordinating a lot of developers, because the ones left developing are the ones you need a lot of (and who need close supervision) to get anything done. Managers will never rock this boat, because their career KPI is the number of people they manage.
Which is not to say they're doing everything right.
Having no track even better. Some people like what they are doing and the field is constantly changing. You want your best surgeons doing operations not managing other doctors.
You need some kind of title so people can feel responsible for career growth and so you can calibrate against other companies' pay at least; it doesn't need to control what kind of work you're allowed to do.
And, as you say, to the degree that position titles mean something cross-company, it gives a point of comparison.
Relevant: https://www.spakhm.com/p/parallel-tracks
"Why did all major software companies settle on parallel career tracks? To keep engineering managers from developing loyalty to engineers."