I feel like the assets and the textures in this game are fine, but the engine is very poor and doesn't do them justice.
Don't get me wrong in general this game looks very nice, but it runs worse than games doing a lot more technically.
It seems to load a lot of things from the hard drive constantly which really doesn't make a lot of sense to me.
Also there is the really low texture draw distance, it doesn't even gradually lower the texture quality its just high quality straight to low quality.
And finally it needs a better lighting engine, and there are no terrain shadows at all.

Also I think with the new engine they should be able to do all this and achieve better performance across the board.