I'm actually interested by the premise of the question. I disagree a little bit with that - if players are looking at mythic raiders doing multiple times their damage... frankly that's a skill issue. As you very well know, there are vast skill gaps when it comes to performance, but the power budget for our gear hasn't changed in years. 1 item level is roughly 1%, that's what it was back in Wrath of the Lich King - Heroic Icecrown gear was 13 item levels higher than Normal Icecrown gear. If anything, I would say the rate of inflation has shrunk slightly; we used to have 15 item level tiers last expansion ,we're doing to 13 this time, and while there is some additional complementary power increase through things like legendaries conduits, unlocking extra soulbind traits, total power budget of those is smaller than... certainly corruption, but even before corruption, essences plus azerite, or your artifact weapon. So yeah, if you look at someone's stats and gear, a 226 chest piece should have 26-30% more stamina and primary stat than an ilevel 200 chest piece, and that should be consistent across the rest of the gear.