Much of the time it's too predictable, to the point it's no longer a simulation.

For example, something like Battle Brothers, where the AI tends to attack the least armored ones. You can put a group of poorly armored people on one side of the map and then put heavy damage ones on the other side. The right side draws the combat which gives the left side space to take out the dangerous targets. Humans would spot the tactic straight away. Setting up I exploitation tactics is not so fun for some people.

A worse case scenario are the FIFA games. Every release has some untested exploit. In some, the defenders often push too high and you can score goals from halfway across the field easily. In some, the goalkeeper gets confused when passing the ball right in front of goal. It becomes less a football sim and more how to get formations that optimize exploits.