I really like the way essenses work and it adds a bit depth to the character! It makes you wanna collect and level the essenses and for that you need to explore all the things about the game, whether it will be m+, Raids, pvp, Island exp
or some other stuff. It feels rewarding and its fun to have specific goals to work towards.
Only negative about this is that its not really exciting or fun when you need to do it with your alts, so maybe some neat catchup feature here would be cool.
I would love to see more of this in the future and it would be cool to bring (back) more abilities on each class/spec that you can unlock through specific content.