If other crafters are like me, they probably have 100's of all the Alchemy ingredients and reagents.
If this is so then, what is the point in the Alchemy Writs, other than getting 600 gold and some inspiration, which doesn't matter at all because chances are you are max alchemy.
Other writs have purposes to do them:
Enchanting, Woodworking, Clothing, Blacksmithing: Legendary crafting materials that are rare and very useful and surveys.
Provisioning: Ingredients and Very Rare recipe fragments to sell or learn.
Alchemy: Ingredients and surveys for even more ingredients. Both that you don't need.
Something needs to be put inside Alchemy writs to make them worthwhile and to encourage people to do them. Maybe add a small chance to get some kind of rare thing. But just, something that gives the excitement of opening the reward bags because at the moment they are just, kinda pointless.
House Baratheon: 'Ours Is The Fury'