8 Division World Champion (even if you don't count the Margarito belt, no one's touching 7 ever again) Oldest Welterweight Champion (record) 6X Welterweight Champion (record) 5X Lineal Champion (record) Champion in 4 different decades (record) Champion across four of the original weight classes (record) Gave up significant size/weight advantage for a decade Started out as a FLYWEIGHT Fighting part time for almost a decade and still performing at an elite level Never stunk out a fight on purpose; always willing to engage and entertain the fans Erik Morales, Robert Garcia, and JCC Sr. have him as the GOAT. Barrera has him as the #2 behind only Ali. Paulie has him as the GOAT (if he beat Cotto, which he did). Lomachenko's strength and conditioning coach has him as the GOAT. Pac's career is breathtaking and will never be replicated again.
To be fair a lot of your bullet points mean absolutely nothing.. Oldest welterweight, champ in 4 decades, giving up size, fighting part time?, and never stunk out a fight are all cool but irrelevant when it comes to ranking.. I'm guessing they were used to fluff up the post...lol
How are some of the points irrelevant? B-Hop and Foreman get a ton of credit for being oldest champs. What you dismiss are feats never to be accomplished again. At least not for a very, very, very long time. Of course giving up size means something. In boxing, size difference is almost always a talking point.
If you had two guys with the same record and the same level of opposition, would you pick a guy being because he's older? This guy was not better than him because his style is more favorable to me? Because even though they're in the same division, one happen to have a bigger body? Yeah it's an advantage and can show how great you are, but doesn't hold as much 'weight' as other qualities because a lot of great fighters fought bigger guys.. He definitely gets credit for doing it though in the now.. We should give fighters the nod for fighting with the most prefight injuries or winning with the least amount of punches too then I guess... I wouldn't say B Hop was better than a guy because he was older when he was champ.. That's just not fair.. He gets credit for longevity but he's not automatically better because of it.. It's just a point to marvel over and say wow.. If I accomplished everything I could as a fighter, should I have to wait until I'm 50 to add to my legacy because somebody else did which makes them better?
If Lomachenko were to go up to 147 next and beat Thurman, it would be a better win than Pac's. This is on account of him being smaller than Pac. If Lomachenko fought for 10 more years and beat Haney at 147 who was considered Top 5 in the division at age 41, he would get more credit than if he did it at age 31. You need to look at the entire body of work and factor in everything including age, disadvantages, etc..
No, Pacquiao wouldn't made it out from 126, Sanchez and Arguello would've killed him, and I don't even what to start on the other divisions...