The thing is, as soon as one lies, the others have to. Imagine being 9 inches and hearing an 8.5 incher claim being 9.5 inches, you then have to "outbid them".
Gals in porn are also being very corporate. If you watch porn actresses' interviews on YouTube, they're saying that Dredd is "at least" 14 inches; one claims that Ferrera is the biggest girth wise; that Lex Steele is over ten inches... and you see them miming a 20-inch space between their hands...
Then, you listen to men, and they either say that "they honestly have never measured" which is hilarious, or they're adding a good 2 inches to their length, and never mention girth -- i don't want to quote names, but even those whose penis has been quite faithfully moulded into realistic dildos, and who are proven to be 8.5 maximum still claim they are over 9 inches long.
I guess they want to maintain their reputation, hire rate and opportunities.
Dredd, who is probably the biggest in str8 porn (?) says he's around 10. He's probably around 9.
I now know my length is porn material and that very few men are longer than I am. I also know thay my girth is big too, but that my length is comparatively more "outstanding" than my girth is. I wouldn't mind being 6.5 around. But that's a girth I could reach easily with regular pumping and occasional fat or hyaluraunic acid (fillers) injections -- which some performers resort to as well.