That is completely and indeed BLATANTLY untrue. Adrienn's field effect more or less spells utter doom for xe's entire team. Samson is fought on a field designed to power up flying moves. Luna's field boosts moves that hit her Pokemon for massively increased damage. Shelly is fought on a field that easily turns into a devastating advantage for your team. And etc. If you actually bother to learn the field effects and how they work they are far more balanced than you seem to think.
Not to mention that you are a person, with a brain. The AI is an idiot. You should be able to outhink it in your sleep. The AI cannot plan. The AI cannot adapt. This is true of pretty much every game, where the only advantage the computer has is reflexes. But in turn-based battles it doesn't even have that.
I like both Reborn and Dark Souls, and in general I tend to think of both as games that reward preparation, planning, and strategy over the more standard brute force your way through (though admittedly I also do plenty of both). And while a lot of Dark Souls players are utter dickweeds the same is true of most fandoms (on the grounds that most people are dickweeds, so law of averages.)