With the exception of the upcoming night blade set, class set are far to niche to take priority over any other sets.
I personally believe they should not be 5 piece sets, but 3 or 4 piece.
This would allow far more build diversity of people picking between 2 very powerful sets, or a strong set, a niche set, and a combo of monster and mythic items.
I primarily play necromancer, but both sets I'm not bothering with at all at this point. I've barely touched IA due to this, it's just not fun going into an activity I know I won't bother using anything from.
Example of neco builds using this suggestion
High end content build:
2 piece maw of the infernal
5 piece relequens
3 piece corpsebuster
Velothi ur mage amulet
Trainee chest
Free roam/rp build
2 piece nerianeth
3 piece corpsebuster
5 piece calurian
3 piece nobility in decay
I feel that making IA sets more viable in mixed set builds will both raise their viability without needing to inflate their numbers.