Specifically: crystals and clusters.

Materia catalysts were removed, which was definitely a step in the right direction.
They gave us a means of obtaining shards rather effortlessly through gardening. However, shards are useless post 50.
I'd like nothing better than to sit down and do some hardcore crafting for a bit once I'm done my roulettes. Wait. I only have 88 crystals. Just the thought of having to burn my evening farming ephemerals makes me shake my head and log off.
Retainer ventures? Sure. 30 an hour will get me maybe one synth. It doesn't scale at all with the demands they've placed on the resource, and there is exactly ONE method of obtaining them in significant quantity.

But it doesn't take long, you say. The point is. it still takes time. Time that could be spent doing something interesting and actually accomplishing a task.They serve no real purpose, other than to fuel the RMT machine and cause gatheres/crafters headaches. Currently, obtaining them is nothing but a mindless grind and completely unnecessary.

So, why are there no seeds that yield crystals?
Why can we not convert clusters into crystals (and crystals into shards)?
Why can we not buy crystals and clusters with GC seals, allied seals or centurios?