Raw HDMI external recorder makes the camera more cumbersome. More cables and more devices constitute a limiting factor, mainly on a handheld operation. Although the external recorder has some benefits derived from its operating system that can facilitate and assist in camera operation, an internal solution is always preferred. Sony understood that and thus made solid efforts to try and eliminate the external recorder of the VENICE 2.
Nikon has implemented that approach as well on its flagship, the Z9. In spite of these cameras having been developed for totally different markets, users, and purposes, they both can record compressed raw without the need of an external recorder. And that is a technical achievement.
Source: The ’Compressed RAW’ Revolution – Y.M.Cinema – News & Insights on Digital Cinema