I am just talking about the metahuman part -
I believe it is needed. I am a designer and modeler, who wishes to create only cinematic movies. I cannot waste time in Zbrush and blender to create an average model, when I can get good quality model right out of the bat with metahuman.
I already have iclone character creator, I can use that as well to import inside unreal.
But zbrush or character creator eats a lot of time. I would prefer metahuman, simply because I can create a realistic human with groom effects, without shuffling through software.
Yes if I have to create a creature or an alien, I will go with zbrush. ( Do not forget we have to rig it also in maya or blender)
Unreal needs to up the metahuman game with more avatars and clothes. With mocaps from miaxmo and daz, we can do wonderful animations with it.