If the top tier stuff is crafted only the economy will be player driven. That doesn't, however, mean you can't drop low end items. I was playing the free UO server Outlands where that is the case. Crafters using the high end materials craft the best items in the game. They also look the best lol. Still other items drop in loot that you are still able to sell to starting out players. Another problem there though is a few players rushed to the top crafting positions. They secured the prime selling spots and basically they control the market on crafted goods.
I like the idea of dropping cosmetics. That makes looting exciting for the player to see what they might get to keep them going on grinding kills yet not change the idea that players craft the usable items in the game. I played Life is Feudal which is a total player crafted economy. Devs said all along that they would only allow animals to harvest resources for targets to fight. They wanted players to fight each other. Their player base dropped so fast shortly after launch they almost tanked. People got bored not being able to kill anything for loot. I saw recently they added some npcs in the game with their own villages. So much for never doing that. Devs will adjust to their player base if they want to stay in business. So the idea that the economy will never change may or may not happen.
Another subject the devs will need to consider is durability of items and how their stats are affected. If items do not degrade then the economy will stagnate without a steady influx of new players needing new crafts. If items do not break then players will never replace those items. I hated LIF durability/crafting system. Items degraded every use even tools. So the only 100% item you made was the first item you crafted. You then had to repair/recycle your tools and even the building you used if you wanted to make another 100% item. It was an awful system.
