Final Fantasy 13 is the only Final Fantasy game I've played. I'm not surprised that a JRPG has a crappy combat system, but I think this one is a particularly good example of a point I'm going to make. First, let me lay out the problems with FF13's battle system:
Low-skill. All the player can do is set which mode the three fighting characters are in, which gives them access to different abilities and AI, and pick specific actions for the party leader; but all of this is a really easy job. Due in part to the backward difficulty progression of the fights (see below) and the infinite mana, most often you just want to leave one party member in medic mode (or two if that's what it takes to sustain health) and the others in attacking mode; you'll win eventually. Playing more skillfully than this basic strategy can make you win faster but it can seldom change which fights you're able to win.
Busywork. This isn't even really a design problem, just a quality of life one. There's no way to set any kind of default action for the party leader. If you want Lightning to stay in Commando mode and just spam attacks, you have to continually press the "auto-battle" button. I think someone doesn't know what the word "auto" means...
The fight puts the wrong half first. This is interesting. In FF13, when you fight several enemies at once, the most dangerous part of the fight is when they're all still alive. That means that if you don't die early in the fight, you know you won't die later; the remainder is just a formality. In a game like Lost Odyssey this isn't as much of a problem because the point of normal fights isn't to kill you anyway but to drain your mana. But due to the way FF13 handles healing (it's an infinite resource) there's no such effect and battles are completely pointless once you know you'll win.
In some boss fights, they fix this by having the boss cast Doom - essentially a time limit. Time limits do solve the fundamental brokenness of this combat system. But they're somewhat lame themselves; besides not having much of a place in the lore, they just expose even more how this fight is not about you or your health bars, it's about how fast you can deal 5 million damage (which, see above, is almost entirely determined by your stats and not how you play).
Little numerical information revealed. Of course, typical bullshit blind-choices.
Enemies have way too much health. This compounds the third problem above. Some bosses took me as much as twenty minutes (and that's with keeping all my buffs on).
The combat in Final Fantasy 13 was never anything but a drag on the story; I was never not thinking, "I just wish I could get through this already and get to the next story event". My point is that this story would have been better released as a movie. Obviously I would have preferred a good combat system to a purely non-interactive medium, but this one was too bad to be worth it. Don't force something to be a game just for the sake of it. The designers clearly didn't understand the value of games, so they didn't understand when a game was not valuable.