Armies would need a supply route mechanic to balance, otherwise it'll lead to "who build the first big army wins"
That's not really true, it wasn't even true back with Civ4's SOD; or, if it is true, it's always been true (outnumber your opponent). There are always opportunities to play tactically, and exploiting tactics can still allow a smaller army to defeat a larger one. It's not like I gung-ho and throw units at the enemy without considering whether they'll even win. I don't know about you, but of course I'm going to prefer attacking only with a very high chance of victory - and generally, I only use units on the following turn or when I undeestimated how much ranged strength the AI will focus on what unit.
You hardly need to simulate supply chains to curtail the strength of armies.
Supply lines in a Civ game I feel would add a really cool addition to the combat, which can sometime be lacking in terms of strategy.
If any game tries, it would have to take care not to make it a micromanagement hellhole, since that is one of the biggest beefs again 1UPT to begin with: pushing units around hexes just to get them in the right position. I guess a trade-caravan type unit could be used: you create an army, create a supply unit, and through a trade route interface set the caravan to supply the army which, though it supplies every turn, can be raided via cavalry attacks or units on the route (though I would argue you're adding a non-obvious additional cost to armies beyond their unit composition).
Anyway, it's possible, but it would have to be examined and implemented properly. In most 4X the supply train is simply abstracted out into a currency-per-turn cost.