P4P exists sure, but it's 100%, completely objective and there's no such thing as a "real" #1 P4P. I could say Jones is P4P, or Aldo, or GSP.
The term P4P might exist and be real, but the "factual" P4P is an illusion full of objections and opinions that are overall meaningless and have no real weight whatsoever.
Did you mean subjective? And yes you could say Aldo is #1 but if 50 other publications including the UFC say Andy is #1 then that will likely stand.
Also how could a fighters record be meaningless? That's what P4P is based on. Have you ever heard of power rankings or MVP awards like all the major sports leagues have? They are based on pretty much the same thing. Win streaks, level of competition, title defenses, skills and dominance.
There is some subjectivity involved as with ALL rankings. However that doesn't change the fact that its real. Think of a musician who wins a grammy for musician of the year 6 yrs in a row. You may disagree but it counts for something regardless what you think of the process.