There are many reasons why a mod might not have made the cut, including but not limited to: I tested many, many more mods than made this guide. I've chosen a variety of mods to suit playstyles and Classic philosophies, from bare-minimum mods to feature-rich addons that you can tweak to your own exact specifications.
This is my opinion about what I found to be the best addons for helping you maximize your gathering professions in Classic, specifically mining or herbalism. While 'Best' is a subjective term, this guide digs into the most popular gathering addons in WoW in search of their best.