> I have never worked anywhere with the L4/L5/whatever crap. No one I have worked with has either. It sounds downright dystopian that people are reduced to a basically a number (if you leave out the L).

This inevitably happens in any large organization. People just have positions like "Department Head" or "Chief Something-Something" instead of numbers.

If anything, engineering/research organizations are unusual because in "traditional" organizations your growth is basically linked to the number of people you direct. In technical orgs, you can be an individual contributor and be at a higher level than many managers.