Rune sockets as an affix on items (replace rarity)

In the interview with ZiggyD it was mentioned that rarity would eventually get removed when there was something else to fill the gap, what about rune sockets as an affix? I think this could work

I'm not 100% against rarity on gear but i think it shouldn't feel mandatory like it is rn, i'd prefer if it was exclusive to jewelry and uniques for example