Marciano & Usyk- They beat the best, but at what age?

[QueensburyRules]

The only two Undefeated Heavyweight Champions, and their 4 BEST heavyweight opponents, and their age at time of the fight(s)......
Rocky Marciano's top 4 opponents:

Ezzard Charles
32 years 11 mos
33 years 5 mos

Joe Louis
37 years 5 mos

Jersey Joe Walcott
38 years 4 mos
39 years 3 mos

Archie Moore
41 years 8 mos



Oleksandr Usyk's top 4 opponents:

Tyson Fury
35 years 9 mos
36 years 8 mos

Daniel Dubois
25 years 11 mos

Anthony Joshua
31 years 10 mos
32 years.10 mos

Derek Chisora
36 years 10 mos.


What, if any conclusions can we draw by examining these ages?

What are the critics always harping on regarding Marciano's record?

Do fighters last longer these days... and did the 8 challengers listed?

- - Most boxing critics dumdums on par with box of rocks.

I've never harped on Rocky who made the most out of limited size and reach to become iconoclastic.