It's true that Rome did have financial interests in war, first clue being how pretty much every single senator was a landlord and a slaveowner. They required passive income to be senators.

So right there you see a demand for land and conquered people. But the military-industrial complex requires modern factories to function. If you did what they do now during Roman times then you'd run out of Romans. The city of Rome was, what?

A million people? Half of them were women, which disqualified them for most military involvement give or take perhaps some interesting exception, and then you had those who were too young and too old. So Rome probably only had a couple of hundred thousand battle-ready troops.

In those days, fresh recruits were a scarce resource. It's not like today where you basically have a surplus of people who lack a necessary role in society.

So yes, I think you raise a fair point in how there's certainly things that are comparable to Rome. But this really is on another level. First clue being in the amount of casualties. Ancient warfare was very tame compared to contemporary warfare. The number of frontline deaths has multiplied since then.

And when you look at the wars that often outline military industry, they're usually very nasty. Viet Nam and Iraq both had casualties in the millions, and they were drawn out for a very long time.

The Romans simply didn't have that incentive to prolong and escalate wars because they had more economic bottlenecks. On some level their invasions had a deadline, they needed to get the mills and the farms and the slave auctions going again or they'd collapse under the pressure of maintaining large armies.