Thinking about "junk" (less than cosmic) gear a bit. Let's assume the difficulty slider has 5 levels to start with.
Here is what I hope happens:
White gear: Base stats only
Green gear: One affix
Blue gear: Two affixes
Purple gear: Three affixes
Cosmic gear: Four affixes
Omega gear: Five affixes, plus omega power
The thinking further, I think it would be great if only up to three "colors" of gear drop at any given slider level, probably blending like a gradient from hero level 1 to 60, and the difficulty of the content scales to match.
For example:
Level 1: White gear (lvl 1-20), green gear (lvl 21-40), blue gear (lvl 41-60), very rare purple gear
Level 2: Mostly green gear (lvl 1-20), blue gear (lvl 21-40), purple gear (lvl 41-60), very rare cosmic gear
Level 3: Mostly blue gear (lvl 1-20), purple gear (lvl 21-40), cosmic gear (lvl 41-60), very rare omega gear (at 60... Well, I wish Omega gear would drop at lower levels than 60, but that's a different issue.)
Level 4: Mostly purple gear (lvl 1-40), cosmic gear (lvl 41-59), omega gear (lvl 60)
Level 5: Mostly purple gear level 1-20, cosmic gear (lvl 21-60), omega gear (lvl 60)
Higher levels of difficulty could be added, and require better upgrades, legendaries, etc. in order to survive.
Would that be good? Would it make gear choices more meaningful again? Trying to think about new players as well as vets.
EDIT: Pumping RIF could "unlock" the ability to pull items from the tier above.