"It" is about so much else. War is profitable for some, true. But it costs money, lots and lots of money. Lots of it!
I don't know, man....try to think of something that's worth more than money; a thing that is worth just about any cost. Got it yet?
It's power, right? It's power. And there are things besides war that create great power.
Controlling trade is one. That's major. Forming alliances. Gotta have that going on, and you've got to collect more allies than your "enemies." That's a must. And, of course, you do that, in part, by controlling trade. Mutually advantageous trade. You want your allies to fare well, but not quite better than you. Naturally, you have to offer your allies (and all that trade) protection from the aforementioned "enemies" (who would have it all for themselves). And the best way to achieve and maintain all this is by forming, or at least encouraging, similar political ideologies, so that everyone involved can keep things moving with minimal friction. Global cooperation is the goal. And there's no question that people can prosper from that, if all goes well. Some more than others, yes, but some, more than ever before (because they started with very little).
So, yeah, I believe very strongly that it's about more than just money.