Harry Greb comes to mind...Billy Conn.
The other difference is that boxing has been robbed of its best by other sports. There is big money in basketball, for example, so why would a talented athlete want to get punched in the head for a living?
In the old days, boxing was the only way for many to make a living.
Ali shocked a lot of people when he asserted that Marciano was better than Frazier, and that Marciano might well beat him. Ali had, of course, sparred with Marciano during their famous computer publicity bout, and rumour has it Ali was hurt by Marciano's body shots.
Ali was heavier and taller than Marciano, had a more scientific style and a reach advantage too.
As you note, old fighters fought way more fights with less time between, and many fought until they were older too (Archie Moore).
Every generation has great fighters, but I think Ry Jones would have had his hands full with Harry Greb. In fact, I think today's heavyweights would think twice about facing him and his like.
These old guys, they were tough.
it's the same old story you can't compare that was then this is now they were tough men then as they are now best leave it at that who would want to pick a fight with any of them way back to the bare knuckle men 100 rounds and more Jess Willard was 6ft6ins built like a brick ****house that Italian Primo whatever his name 6ft 8ins you ought to get a book on the past champions makes very interesting reading Max Baer practiced his punching power slaughtering cattle with an axe get a book you won't regret it these men were much tougher than you think even by todays standards
yes they were tougher, fought more often, fought longer rounds 15 rounder's some fighter's fought 45 rounds.. Don't recall the fighter's of the past using any enhancement's
I would say that today's boxers are better because of improved:
1. training techniques, and,
2. diet.
Non-heavyweight boxers. Heavyweights have, in general, gotten bigger [so people assume they're better] due to new training techniques but non-heavyweights are not bigger.
In the last 70 years, boxing techniques haven't changed [thanks to standardized rules & glove size], only trends have changed [watch Charley Burley or George Benton fights for proof].
70 years ago; most boxers were far more active than today & they tended to have unparalleled ring experience.
Today; fighters are generally better primed with months in between bouts to better prepare themselves for the fight.
Which is better? A fight ready champion 70 years ago or a fight ready champion today?