"Turns out we can beat the hardware with triangles much bigger than expected, far past micropoly. We software rasterize any clusters whos triangles are less than 32 pixels long." - https://advances.realtimerendering.com/s2021/Karis_Nanite_SI...

It's not just micro-triangles, it works for triangles that span multiple pixels. And that's not a special case, that's the standard nowadays, except for games targeting very low-end devices.

The dedicated hardware is nice for general-purpose support for arbitrary triangle-soups. But if you structure triangles a certain way and have a certain amount of density (which you want for modern games), you can specifically optimize for that and beat the general-purpose hardware rasterizer.