So just using one factor here however; there are plenty of other examples I could use in the game. But for sake of length and annoyance factor I am only going to use the new mod 16 weapon sets.
The Alabaster set is acquired by running a Master Expedition and awarded once the quest is turned in by RNG chance. So you have 3 chances per day to get the set. The MEs are easy, take a bit of time but fairly easy even solable on one or two runes, but I am sure there are a few who have soloed on 3 rune runs.
The Watcher set is acquired by running a Master Expedition with a chance that a "puppet" spawns allowing you to give it an essence to spawn a new boss. The problem here is that to acquire the essences you must have completed the Lair of the Mad Mage at least once before they start being rewarded in the end chest. This means prior rewards before you can even begin this task. It doesn't stop there, you must also have a decent party who are able to handle and defeat the new spawned boss. Then on top of this if you were successful in defeating the boss, there is a One in Five chance (5 party members) that you will be rewarded with a watcher weapon drop. However; it gets worse, you have a One in Eight chance that the weapon you got is for the class you want it for (meaning your main class).
So clearly the second weapon set is much harder to obtain but when you compare the two weapons they are so similar in what they do that the extra that the Watcher set "might" give is so negligible that its not worth the effort. The pay off for trying to obtain the Watcher Set is not enough for what is involved in getting it.
This is The Cloaked Agency and Storm Kings Thunder all over again. If you have playing during these campaign releases you will already know where I am headed with this argument. But if you are new, you wouldn't know the grind and the insane requirement to restore the artifact weapons from these campaigns that were immediately rendered obsolete when the next new mod was released. In some cases to restore just one piece of the set would require six weeks of grinding and another six weeks for the other piece. A total of three months just to get a set that becomes useless in a few months.