It's a bit of a crazy idea, but im throwing a hail mary since crafting in this game is about the most rewardless thing there is.

My suggestion is to make it so that some items can only be obtained and used, if you crafted them yourself. Maybe make it so that only some vanity gear is crafted/untradable. The way I see it, this would actually make crafting more enticing, and would motivate more players to level their crafting classes. Furthermore, those that do level their crafting classes will feel more rewarded. This would also slightly help the economy because more players leveling their crafters, more materials are being bought.

I know some people will be opposed to the idea. But i think that crafting is quite fun in this game. And quite frankly it isn't that hard to level when you take advantage of rested XP, the XP manuals, and leves.