Most of the modern “training” is crap.
Boxers used to fight 45 round fights.
Now they fight 12 round “championship” fights.
Heavyweights Jack Dempsey and Jess Willard (6’6 1/2”) used 5 ounce gloves in their 1919 title fight.
Today lightweights use 10 ounce gloves.
I agree, somewhat, but, the records for timed events, height, and distance have been reset many times since the old days. That has to tell you something. 5 ounce gloves are very hard on the hands. I’ve personally knocked out 5 opponents with 16 ounce puff gloves when I weighed 170 lbs. As far as heavyweight boxers, Rocky Marciano was probably the best ever, IMHO. And no, I’m not Italian.