If you look at the example Nanite meshes that come in Epic made projects like the Valley of the Ancient they're not raw 1GB meshes. So the idea that using Nanite means you never reduce the polycount on meshes or do any kind of optimization isn't something that's practical. Even for non-realtime rendered projects (eg: film)…
Nanite is cool but The thing is, just because you can render a 5 mio mesh does that not mean you want to work with a 5 mio mesh. Painfully slow export and import, terrible UV mapping, crashes memory issues, insane repositories, long pull and push times, bloated harddrives Then we get things such as scripting, booleans and…