The Nikon Z8 at ISO 12800 produces files that are usable for print. This is the relevant benchmark. Not that the files are clean — they are not, in the way that base ISO files are clean. They are usable, which means the noise structure is fine-grained rather than blotchy, the color noise is manageable, and the luminance noise in shadow regions responds well to noise reduction without smearing detail. On a night street, ISO 12800 is the thing that makes photographs possible that were previously impossible without flash.