Eh, as a datapoint, I also have no degree. I worked at google for a few years as a contractor (with 15+ years industry experience before that) - A few months back, I interviewed and was hired on as a L4 (L3, as I understand it, is where you come in after college, L5 is senior.)

My personal impression is that it was pretty clear to all involved what they'd need to pay me, and they slotted me in at a tech level that made that ask reasonable.

(but then, I think that ask really was reasonable for my skill level and the current market, if anything in this market can be seen as reasonable, so I guess in the end, that means the same thing as slotting in my level based on my skill level. But google and the contracting house both had a lot of information about what I was willing to accept, and about what other companies were willing to offer me. I have a very open negotiating style.)

My other impression is that I totally would have had that senior title at a smaller company, but I wouldn't have gotten paid any more, so again, the money seems to be the honest signal.