>>533566713
Are they really? The best you can get is 20% from five Mama's Beads, which is hardly enough armour to get you through the final fight. Why would you do it without a suit in the first place?
And with a suit, due to how resistance calculation works in SoC, your max armour value will be 68% in a perfect condition exoskeleton, or if you wear a SKAT suit, 64%, where the artefacts only contribute 8% and 9% of those values respectively.
Compare that to the elemental artefacts that can get you to over 150% resistance. Are those 8-9% extra armour really worth occupying all five belt slots?
They're really only useful in the early game, when you have shitty armour or none at all; the better your suit gets, the less effective they become.