In a few decades we'll have robots to fight our wars.

I find this very unlikely. Maybe most of the shock and awe part will be done by robots, but I doubt that there won't be boots on the ground. Nor do I think that we will do away with sailors on destroyers.

I would wager that a lot of the people wasting time playing video games all day are precisely the ones who would benefit most from serving in the armed forces. Traditionally that is probably where a lot of them would have ended up.

15 years ago I failed out of computer science at UIUC because I skipped class, got high and played video games all day. Once my parents cut me off, the depression of working dead-end jobs after having such high prospects before led me to enlist in the Navy to try and start over.

Today I’m married with a child, I support my family as the primary breadwinner, I have a BS and MBA and am pursuing a PhD in computer science. All of that education was paid for by the GI Bill.

Sample size of one, but I can confirm your hypothesis.

You're right, they would be the ones that would benefit the most. Unfortunately, since many of them are already on disability and have prescriptions for certain drugs they'd likely be disqualified from service. Barring an actual WWIII scenario and a draft that would waive these restrictions, "join the Army" isn't an option.

As cannon fodder to protect the privileged.

That's actually one argument people make for reinstating the draft.

With the draft, people from all walks of life were enlisted. (Yes, there were ways to weasel out of it, but beside the point)

Without the draft, the army is largely built from the lower-class, conservative, patriotic populous.

The argument is that the privileged would be less likely to send people off to war if it meant their loved ones lives were on the line.