Albion Online's Point Is Very Insightful
In a sandbox game with a limited amount of content, compelling compulsion loops are worth their weight in gold. Regardless of the original intent, laborers have become one the cooler aspects of AO.
I'm pretty much capped on everything, since I need T6 mobs to gain any combat fame, so unless I have a group that is willing to risk a red zone dungeon during prime time, my progress has pretty much come to a halt.
However, the one thing I can ALWAYS make some progress towards is filling books. Filling books is what drove me into red zones, since the return it provided made it worth the Albion Mall of losing all my gear, all my books, all my tools. All that mattered was if I could fill one or more books and make it out of the zone alive. And the really awesome part was the hope of finding a rare legendary or mythical hide/resource that would fill multiple books.
Best of all, there was no getting it perfect. If you did get some rare returns, you'd always think, "Damnit, why didn't I take more books with me?!" If you got ganked or came up empty by Albion Online Gold, you'd curse yourself for having brought (and paid to travel with) so many.
Once my laborer hit T7, that (and only that) is what drove me to risk going into a black zone, since, if I could get lucky and fill a few T7 books, I would be set for at least a couple of days.
In a lot of ways, most of what many of us in the game do, revolves around ensuring we're filling enough books to maximize our laborer returns, since it feels "wrong" to have one sitting around not bringing in resources, even if they're just lower tier ones.