Absolutely not "all", a massive amount of management (non-commission and commissioned officer) time is spent policing the behavior of 18-22 year olds, frequently including dealing with their criminal behavior both in and outside of the military. In 2021, the latest year DoD has reported, 2.6% of active duty military were kicked out of the military for either failing to do their jobs or criminal behavior.^1 In 2020, it was nearly 3.1%.^2

This is the small fraction of people who were even willing to volunteer for the military, and then completed a significantly more strenuous recruiting process than nearly any private sector job. Having a sucky life in return for learning job skills isn't worth it to most Americans of any age!

Also note all branches are having trouble recruiting the last several years, to the tune of 25-30,000 recruits short this year. Again, most people do not want to do this!

1. https://download.militaryonesource.mil/12038/MOS/Reports/202... pg 50 shows active duty separations by type, I refer to Military Requirement/Behavior/Performance and Legal Issues/Standards of Conduct.

2. https://download.militaryonesource.mil/12038/MOS/Reports/202... Similar to above, pg 46