Yeah the entry base pays not great but you do have to keep in mind that there are fewer federal taxes taken for some forms of pay from the military. At lower ranks you also get a barracks room free so you aren't paying rent (or utilities) and you can eat in the mess hall 3 times a day so technically you don't need to buy food. There is also a clothing allowance in addition to your base pay so clothing doesn't come out. You also aren't paying premiums for medical, vision, or dental either.

Once housing, clothing, utilities, insurance, and food are covered that $23k a year isn't as bad as it looks.