I don't want to be a Principal/Staff or a manager. This is at a FAANG; I'm comfortable with my salary and work; it's reasonably challenging and not overly easy, and while this sounds utterly ridiculous to some people, I don't need or want to care about another 100k in stock/40k in salary.
I'm scared that "stagnating" in a job tier will result in eventually being cut for not improving or being promoted. I see this happen in the new grad areas frequently, where they kind of just get kicked out if they aren't good enough to title up within a year or two.
These levels are probably not coincidental: L5 is when you're expected to be able to work independently and have the organizational context to make good decisions and contribute usefully with minimal manager support. Before that level you usually cost more in management overhead than you contribute in output.