Speaking personally again here - My biggest gripe with Eureka is that it's nothing but bland shallow systems and one dimensional gameplay.
Why isn't there more challenging/engaging stuff in there? They could have easily designed Eureka to be more robust, and then added in FATEs, NMs, and AFK farming singular mobs. That stuff is lowest common denominator derivative content. Instead of being the main hook of Eureka it should have been the stuff they added a week before launch...This way everyone of differing playstyles can enjoy the level of engagement they like to get the reward they want.
This is not an insult on anyone gameplay skill level, but an insult on the developers competency and creativity. I'm 100% confident that a fresh out of college part time intern could have developed the current iteration of Eureka: Anemos in the time frame they had for it.
To be fair, I don't think we should EVER have battle content that is considered relaxing. That's like saying Oh I like getting diabetes...I'm all for varying forms of side content being relaxing, but battle content needs to be engaging. That's its hook.