As it pertains to doing the majority of jobs in the military they are. I never had to knock out 42 or more push ups in succession in the performance of my regular military duties.
I have friends who were Frogs, RANGER, EOD, SWCC, and all manner of pilot or aircrew. Never have any of them regaled me with tales of how being able to do push ups was useful in real life, let alone operational or combat situations.
It makes more sense to have standards that test cardio and / or endurance like a 1.5 mile or greater run and move on to full body exercise or exercise based on a percentage of bodyweight or actual operational needs. A combat Marine needs to quickly buddy carry a wounded comrade 40 meters more than he needs to knock out 40 push ups.