Trouble is, there’s a lot of people who just want to put everything that’s absolutely bleeding edge into their product, thinking it’s going to make it better.
They want the biggest landscape you can possibly have ( why can’t it be even bigger?! ), with a totally realistic ocean, ideally on a totally real planet in a totally real universe, where you can really fly from one planet to another, everything has to be Nanite with Lumen, with super anti-aliasing, and metahumans wandering everywhere, no doubt able to hold conversations, using AI… ( and so on, to infinity ).
If someone’s’ going to make a crap game, having the largest landscape possible with the most high poly meshes, amazing lighting, which takes out the neighborhood streetlights when you boot it up, is not going to save you. It will just be a crap game that uses a lot of resources.
They have no idea, that you can quite easily make the player think this sort of thing is going on, without even 5% of the resources, just using clever shortcuts and everything that was already available in UE4.
They don’t understand all these new things are tools that you might use. It’s not compulsory 
I’m sure Nanite will be the default, and be great, in the end, over time, when everybody, including all the players out there, have jumped up to the next generation of GPUs. But right now, it isn’t quite there.
I think Lumen’s going to get there first. It does look great, and is a pretty good take on static lighting.