Again, so happy for you, but you are playing 22/12 Censure Purifier with a Conduit and melee support. How does example can even be extrapolated on rest of IK builds?
I even made a guide to Chaos Pyro wearing IK set, dude.
I know exactly how it plays. It has Sigil of Consumption, additional physical resist, 100% poison res (so you can overcap other res easier) and permanent damage absorption. It’s nothing like a Shieldbreaker.
Here is a Shieldbreaker that I have made based on IK set.: https://www.grimtools.com/calc/lNk6rXRZ
It has so many defensive layers on it: converted Bat, Ghoul, 20% phys res, 12,5k HP, huge max res, cc-res, double movement skill, cdr, etc. etc. And it feels and plays like a complete glasscannon.
You can’t be making “set is all right defensively” argument by giving examples of tankier archetypes that wear this set. Instead you should try and compare it to other caster sets to see where it stands.