Please send this as feedback:
Visibility buffer rendering speeds up rendering for opaque’s but Nanite is too heavy and complex.
Give devs a way to use Visibility buffer rendering without Nanite and it’s overhead.
Not everyone prioritizes disk space over performance:
The primary reason to use lower resolution Nanite meshes is to save on disk space. The performance of lower poly meshes may not be intuitive or like you are used to. Commonly that won’t improve perf. Sometimes it can even be slower. YMMV.
From Brian Karis himself, from this comment.