alot of light heavies are former middleweights (but then alot of middleweights were once welterweights, welterweights once lightweights etc etc), but Jones was a natural light heavy and hopkins purposefully put on 15 lbs of muscle to go from middleweight to light heavyweight division and unlike alot of fighters this extra bulk made him at least as good a fighter
I've been watching boxing since the late 1970's. The professional
lightweight, welterweight, and middleweight weight classes have been far more competitive than the lightheavyweight division over the past 30 years.
Off the top of my head I could probably name two dozen great boxers who've fought most of their prime in the lightweight, welterweight, or middleweight divisions since the late 1970's. Your comparison of boxers moving up in weight class to light heavyweight is ridiculous. Without looking on Ring Magazine's website, off the top of your head, name 10 great boxers who've fought most of their prime as light heavyweights in the past 30 years?