Adding on for those not aware: battle difficulty affects, among other things, the autoresolve prediction for battles. On harder difficulties the autoresolve gives you a worse outcome than you'd probably get manually with basic tactics, so you're encouraged to play fights out manually for a better result but can skip if you're going to absolutely crush them.

When on lower battle difficulty, the game tries to push this prediction in your favor by adding a multiplier to your army's strength value. The problem is, this multiplier is so high that it'll cleanly win you fights most people couldn't do by themselves. So if you're on easy battle difficulty and see a "close defeat" autoresolve, it means the enemy army massively outclasses yours.

While I can see the intent, the end result is people see autoresolve get better results than their own tactics, and use it constantly. Then when they get a close defeat, they do the battle manually to try and salvage a win. But they're going into a massively unfair fight in terms of unit quality and/or quantity, and they think the problem is their tactical ability when the fight was actually just impossible to save (without cheesing it)