‘Native’ tvOS apps are way faster and more flexible in what features and functionality you can do, but you don’t get access to a standard TV UI library. Native developers have to reimplement all of the OS-level behaviour themselves, if they want to replicate this which is a lot of redundant work.
This may be a very developer-minded request but what I want Apple to do is add a TVUIKit library to the native app side. This would include things like the system autoscrolling labels and smart headers in collection views. They would effectively be stylised UIKit controls, which don’t really fit in the core cross-device UIKit component library, but are used across tvOS apps. Then, developers don’t have to painstakingly recreate behaviours that you get free with TVML whilst also having the speed and utility benefits of native apps.