I found this comment a bit unfairly grayed out when I first saw it and want to add some nuance to this, as a person who left the Army due to physical disability caused by training rather than combat.
Training is the core of what we do, and extremely important no matter what. But, the nature of the training often doesn't match the real job. For instance, I remember at LDAC, a required ROTC summer course where you get evaluated and stack ranked prior to being given a job, there was a woman on a guaranteed nursing scholarship who was probably about 4'10", 80 pounds, and she tore both ACLs from all the marching with 90 pounds of gear. Forcing cadets that you know for certain are going into healthcare fields to train as infantry is no doubt harmful and unnecessary. At the time, women weren't even legally able to try becoming infantry, but still forced to do the training.
Personally, I served in a combat job, but even then, a lot of what we did felt more like hazing and dick measuring contests than skills-related. For instance, in a Cav unit, we were all required to do spur rides until passing, which involved activities like carrying telephone poles up and down hilly trails for 12 miles at 3 in the morning after not sleeping for 48 hours. I have no doubt doing stuff like that contributed to the spinal degeneration I eventually lost two years of my life to after leaving the services. Nonetheless, being a large, physical capable person who played and excelled at sports my entire life, I enjoyed that type of thing at the time. In retrospect, though, it sure looks wasteful and stupid. The repeated forced sleep deprivation is especially egregious, as it seems like the top contributor to all the accidents, and as far as I understood, training in a sleep deprived state doesn't actually improve your ability to deal with sleep deprivation in theater. At best, it helps to weed out and select who can and can't naturally deal with it, but it isn't really trainable.