In a low pop situation, there's an issue where players levelling professions want to buy materials, but there aren't any to buy, because the purchases are so sporadic that it's not worth it for gatherers to continuously list items. End result, people need to level an alt and farm their own stuff or they don't do any of it and quit, because that kind of thing is not what they want to do with their time.
A simple way to alleviate the issue of lack of supply is to increase the listing time to two weeks or one month, depending on how low the population is.
Personally, not having much to buy when levelling is a disincentive to play here and part of why I haven't bothered over the years (My original account from years ago must have been deleted at some point, because those log in credentials didn't work, so I just made a new account a few months back. No big loss). It's a great server, but it feels almost as empty a running my own solo server without any of the benefits of doing so. Not a complaint, just an observation; I may just go back to playing on my solo server again.