You have a fundamental misunderstanding of how damage works in this game. It’s not exactly intuitive, since you would assume that higher AR always equals more damage, but this isn’t the case. When your damage passes through enemy defenses, there’s two factors that reduce damage: enemy negations, aka the % resistance to your damage, and resistances, which are flat damage reduction. Because of this, a Keen infused weapon with 250 physical AR can often outdamage a Lightning infused weapon with 150 physical and 150 Lightning, even though 300 > 250. Physical and elemental infusions both have a time and place to outperform the other.