look at nighthold for example
LFR tier- 860
normal tier- 875
heroic tier- 890
mythic tier- 905
ilvl cap- 925
I feel like the hardest content in the game should be closer to that ilvl cap, not 20 ilvls of RNG, you could farm the current tier for 5 months and not truly get "BIS" gear.
I don't care that LFR players can titanforge an item up to the same ilvl as mythic gear, but mythic gear should be closer to that ilvl cap, say 5-10 ilvls.