Lot of people here complaining on how dumb AI is. If they upgrade AI then the farming will also gets harder that's why its ok if they're dumb you just need to make your Auto duel deck basic so AI can handle it.
NPC AI and Auto-Duel AI are different, though.
High level NPC AI makes lots of good choices compared to Auto-Duel AI.
....Which is to be expected, anyway. This is a card game and you're the duelist, so most of the time you should be the one playing, even against NPCs since that's still Dueling too. That's why they made the Auto-Duel AI dumber.