So the background for this post is the description of artisan classes and professions described here:
https://ashesofcreation.wiki/Artisan_classes
Currently, one player can master all the professions within one of the three artisan classes (gathering, processing, crafting). While I understand that mastering all professions within an artisan class will be time consuming, one can imagine a few years down the road where there will be a significant number of players who have mastered all the professions within an artisan class, such as gatherers who are max level in every gathering profession.
I suggest considering limiting each player to getting max level only in one profession (such as mining), instead of an entire artisan class (such as gathering). This will make each character more unique; encourage trading and other interaction among players since one player will not be able to do everything within an artisan class; create risk and reward in choosing which profession to max out (instead of one player being able to gather whatever is in demand at a particular time); and generally make the professions more valuable.