It still means something specific. It's an extrapolation of the transistor density. The design rules on state of the art processes are too complex to summarize with a simple single number like in days past, so this is a reasonable way to describe things. The argument that they're purely meaningless marketing numbers is just tired empty smugness. When we talk about TSMC 7nm everyone knows what that means and that it is indeed a significant advance over the prior nodes. The numbers capture the advantage in rough terms, as best you can.