Why are we so biased/obsessed with old fighters/era's

Canelo would have to fight them in Hagler's era.

He could have made 160 when he was very young, but that version would get beaten by Hagler.

 

Fighters still rehydrated on same-day weigh-ins. It was just more dangerous as they drained on the same day. But their opponent was equally drained.

Look at Marvin Hagler. 5'9 built like Bradley on steroids. Do you really believe he only weighs 160 fight night? lol.

 

They couldn't cut as much as they do today. If they cut a lot they would ruin their stamina.

Hagler was a cardio-monster, it is unlikely he cut significant weight.

Canelo definitely isn't making 160 and fighting on the same day. He will simply fade as the fight progresses.