H2H he's a monster. Most people have him in the top four for lightweights. Personally I have him #2, just behind Duran. I can't argue though if someone put Armstrong and B.Leonard ahead of him (h2h). As great as Joe Gans was, h2h he would suffer from fighting well before the evolutionary arc of boxing that peaked from the 30's through the 50's.
Resume wise he is quite thin really at 135. H2H you can argue him much higher. P4P he rates well too with his achievements above 135.
Holding Chavez to a draw was a great accomplishment but it didn't happen at 135. Still, I believe he is in the discussion.
He's one of the four boxers that I believe could be mentioned as the GOAT, along with Duran, Gans, and Leonard. Unifying the titles and looking completely dominant at the weight (maybe even more so than the other three) works in his favor, too. Like, I have him number four, but I'd listen to an argument for putting him in the number one slot.
He didn't hold Chavez to a draw. He clearly beat him and suffered a terrible decision which was universally recognized as such ..
No, but he's damn close, and quite possibly the best of the last ~fifty years. The best of all time is probably Joe Gans or Benny Leonard.