You find this argument regarding role-playing games about whether armor should absorb damage or make you harder to hit. (GURPS tried to make it do both, but I believe they gave up on that in 4/e.) It is a silly argument because tabletop RPG mechanics can’t be complicated enough to really simulate the difference.
But forgetting that and just considering the question...I’m going to think-out-loud on a topic I am far from an expert on.
Armor does absorb damage. But because it does, it would be foolish to aim a blow at the armor. As anyone can quickly discover. So, one instead attacks the gaps in an opponent’s armor. Which is what the period fighting treatises advise. So, the upshot is that—in practice—armor makes you harder to hit rather than absorbing lots of damage.
Well...no doubt there are exceptions. Some weapons are designed to minimize the effect of certain armor. Even then, attacking a gap will usually be more effective. So, I think this is indeed the exception rather than the rule.