I wonder if many people agree with dragif2's point above that warfare feels like dominant strategy?
If by dominant do you mean the only strategy that works at certain difficulties, no plenty of peaceful games have been won even on deity. If you mean is it the "superior strategy".... that answer is yes.
The reason for this is quite simple...that's the way Civ 5 mechanics work. The first notion, when I conquer someone's city...I am not only gaining benefits, but I am denying an opponent those same benefits. 1+1 is better than 1 so to speak, so already there is a big bonus to war.
The second comes down to the cost of war. Initially, war has a fairly significant cost, it takes a lot of hammers to build up your military, hammers that could be used for economic infrastructure. However, once that is done, the cost of engaging and maintaining wars is relatively low for human players. Humans learn as they go up in difficulty to maximize unit efficiency....to ensure units are not killed. While the AI begins to lose unit after unit, the human does not. Healing is "free", so other than the cost of upgrading your armies and unit maintenance, warfare is relatively free for the human after a certain point. So from a pure economic standpoint, warfare + an economic engine is better than just an economic engine.
Now you can tweak numbers and the like....but the superiority of war is baked into game, and was long before VP got a hold of it. Honestly if you wanted to change that paradigm you would probably have to make some pretty radical changes. For example....remove unit upgrades completely. If a civ had to remake its military every era to go kill someone....warfare would not be nearly as beneficial as it is now. But upgrading is a ton of fun, and there would be numerous balance considerations for such a radical change...but its an option for those who might want to modmod. Another radical idea, make it cost gold to heal units...again now warfare has a much steeper economic price...but lots of considerations for such a big change.
**And just to be clear, I am not advocating those changes in the core mod. I do not think they would be a benefit, they are just ideas for mod modders who might want to tinker.