This is about essence gathering. It's harder to get than anything else. It wasn't before.
Wisp Isle is not good for anyone needing enough essence for construction. There just is not enough of each resource and the various tiers are partially mixed together which makes it even more irritating. And there's no vault and no portal there. If you asked, many crafters would tell you they hate Wisp Isle.
Ever since the residue appeared on Istaria, wisps have mostly gone into hiding. The existence of residue would be okay (although I feel like I'm walking in snot) if the residue gave more essence. In some areas there's not enough residue either. There are supposed to be wisps that give you more of the resource, but in practice, most wisps are "weakened" wisps. I have yet to find one glowing or pale that is not weak.
Someone told me that safe areas have fewer wisps so I went among the treants and didn't find any wisps there.
So, I am suggesting that residue leaves and the wisps return. Or else, have big mounds of the goo. A few, please!