Fates struggle as a concept because they are a lot of hassle vs. reward.

It's not fun to complete a fate, then have to trek across the zone just to start a new one. Possibly getting there without time to get a meaningful reward. Contrast with dungeons, which give you a ton of exp bonuses, gear, etc, and you are generally earning exp the entire time you are inside. Fates are honestly best used while waiting for a queue for something better--honestly, I feel the game would do better without them and introducing something different.