I dont think this has anything to do with worth - its just a good advice. There is no objective measure and you likely underestimate what you are "worth" to so

I dont think this has anything to do with worth - its just a good advice. There is no objective measure and you likely underestimate what you are "worth" to some companies. As a consultant it might be different because roles are different and you aren't really talking to HR at that point, e.g salary negotiation