Shards system loses after campaign

Lately I was thinking about what is the weakest link among LE mechanics. I think this game has the best approach to looting and crafting which makes looting from the ground actually meaningful and crafting on point random, smooth and fun. Forging potential is just great innovation. And while looting and crafting is fun I feel like shards system is a bit off. Shards are interesting in the early game, they make a little bit of sense in the early-mid game when there is need for rare affixes shards, but they become completely meaningless in the mid to late game as by that point player has so many shards and the only bottleneck for crafting are good bases. So basically after campaign/early-mid game player treats shards just as unending resource that he has. I'm never actually looking for shards drop, they just explode and sometimes I loot them, sometimes I ignore and run past. I think there is a lot of potential and I have some thoughts on how this could be changed to bring joy to looting and managing shards.

I have only scratch of what could be done there so please don't be harsh on me.
What if shards are split into a few groups, just for example common, rare and very rare. And affixes are associated with those groups can be crafted with those shards. For example any resistance can be crafted with common shard, hybrid health only with very rare shard. Also there could be tiers of shards from 1 to 5, so to upgrade some common affix to tier 3 player would need at least tier 3 common shard. Maybe even add very very very rare(like only uber aberoth 0.001% drop) tier 6 and 7 shards that allow to upgrade affixes to exalted ones from corresponding group. That should ease balancing of shard drops in campaign and late game without artificial level requirement to craft additional affixes, plus it could make dropping and managing them actually exciting, making player look for them when they drop and think about what he wants to upgrade.