I haven't played much GW2 myself but as I understand it one of its problems is that it actually gives players "too much loot".
the problem is that when everything you do gives you loot. then most of that loot is actually going to be junk, and the probability of getting something actually good is actually really really low.
In many ways XIV has similar problems. the accursed horde sacks in palace of the dead for example. theoretically a great idea that guarantees loot rewards when you collect them and encourages exploration. but the reality is generally speaking those sacks are completely ignored by the players because all of the rewards from the sacks are generally rubbish and not worth the effort of getting. better to just go straight to the portal and go to the next floor..
chances are the next deep dungeon thing they want to do will have a similar problem. the rewards from those sacks and things will be junk and simply ignored by players.
treasure maps and aquopolis / canals are much the same most of the rewards from them are worthless junk and thus many players just don't bother.
Retainer ventures are much the same. and have killed the market for so many things within the game. especially when your retainer can bring back an entire mansion glamour or something such...
this is also the problem players have with games like Diablo 3 and the division. both of which typically make loot rain from the skys and reward players with absolute bucket loads of it some of these you can literally get 50-100 items over the course of a few hours. but the likelihood of players actually getting an upgrade or something they can actually use is incredibly low.
when games throw so much loot at you it creates a problem of value or lack there of. so much of what you get given holds so little value that's it's basically worthless. and then are you really being rewarded for participating in that content when the loot you got was worthless trash....
In a way it's like running sirensong sea in a levelling roulette at level 70. you're guaranteed to get a piece of loot at the end but it's useless to you.
the same would be true if expert roulette guaranteed loot at the end. it would be one of those useless greens that is absolutely worthless to most players and just gets turned in for a few seals.
it's also why you quite often run an entire roulette and don't even bother opening the chests. the loot is worthless.
those games typically throw too much loot at players and loot has no value as a result of its sheer abundance. you can be getting hundreds of pieces of loot but still feel like you are not progressing at all...
Seems to be quite a common opinion among people i know that have played it and why many stopped. because the loot you get is worthless. so you never really feel rewarded at all.
that's partly why i never really stuck with it myself even though i didn't get as far as many of them.