Internet claims the existence of various sources for the "unreachable" usage in the early 1900s, which sounds about right.
I'm pretty sure the more common uses of "what you personally pay" and "making a monetary loss/broke" have been around for longer than that, but it's not relevant and I'm on phone and not going to go hunting for historical examples right now.
I'd guess the "unreachable" usage has fallen off over time, but I'm not sure, and I don't even know how prevelent it was at peak usage, or even when peak usage was.
Does anyone know the origin of the newer "unhinged" definition, btw?
Offhand, "do they read the paper or watch tiktoks?" is probably a decent proxy for if someone is in the "unavailable" or "unhinged" group, complete with the overlap zone in the middle.