And with the decline in birth rates armies are going to have smaller pools of people to recruit from. Even the US army is experiencing a shortfall, and it's not getting better any time soon. Perun did a great video of this just recently.
It makes sense that if militaries won't be able to recruit the quantity and quality of troops that they would like to, they'd need to supplement those numbers with some kind of force multiplier.
It's like the Fonz jumping the shark all over again.