The meaning is so much different now since the SRR days. It simply meant the best fighter regardless of size. People typically use resume/accomplishments now. Subjectivity leads to a lot of bias. Fans who use context have a better chance of gauging who's the top 10 best fighters. I think P4P was meant to be a fun idea, but now it's taken way too seriously now.
I think they've always been fluff. Unfortunately people take the 'title' super seriously these days and try to sneakily climb weights to establish themselves as p4p talents without taking on the biggest challenges.