@High Cross
Concur. It is astonishing how many fights, even those at a championship level by professional combatants (e.g., Fury-Wilder III), are decided by the last person who becomes too exhausted to remain effective. It seems that the strength necessary for fighting is less than one would think, but the endurance is (or can be) much greater.
Sidebar: That's one of the reasons I've changed my workouts to maintain what I think is the necessary strength while focusing more on improving endurance.
Ducas