Why UE4 isn't using Enlighten?

Thanks for the clarification Daedalus51 but i have one question when it comes to dead island 2 … The game was clearly designed to be a kind of open wolrd game, like Far Cry, The Division or MGS V etc…
And GI was clearly a big point from what i have read… Why you guys simply didn’t used Directional and SKY light ? What was the reason to try alternatives, scene quality ? Performnace ?

My point about GI is, no matter if we are talking about Lightmass, VXGI, SVOTI etc… It makes a game more pretty and even realisitc. If a good GI solution is not that important, why have you guys tried so many different systems ? Why not making things easy and simply just keeping directional and sky light ?

Just forgot to ask, have you guys at yager every played with VXGI around ?