If you ask about in PE zone chat, you will often hear variations on 'Don't worry about gold', and 'Gold isn't important in NW'. This is true to an extent, though devs have tried to make gold a little more useful lately, it remains an under utilized currency.
Gold seems valuable when you first start playing, as it is a means to getting various low level supplies. Profession materials, potions, health kits, and even mounts are all purchased with gold in the early days of playing. Nearly all of these are better purchased using AD after you achieve max level.
You will find in the long run though that those guys in p.e. were actually right. For the most part after achieving level 70 the main thing that Gold is used for is moving enchantments in and out of gear as you change up your loadout. Recent changes to professions and campaigns have added more uses, as you can make vouchers that may be important to levelling a stronghold.
Recent mods have added significant value to Gold for the level 70 player.
Stronghold: For the stronghold coffer vouchers can be made through professions and the campaigns. Most but not all campaign currencies have vouchers available. Important ones are Frozen, Fey, and dark currencies are available through the campaigns, as well as gems and surplus EQ that can be made with professions. These tasks take gold as a consumable, often 5 gold at a time.
Mod-10.5: A new style of fishing was introduced with mod 10.5. Its necessary for getting many of the componants needed to put together the new artifact weapon set. One of the 2 styles of bait available is sold for voninblood (no one does this) and gold (everyone does this). This takes significant quantities of gold if you spend a lot of time doing it. On the order of 50 gold for a good long days worth of nothing but fishing. 99 lugworms are ~10 Gold.