I have a z9 and if you are a Nikon shooter, the z9 af system is easy to understand. I used to shoot a D6 and there is very little learning curve when setting up a z9 af. Sony and Canon has gone a different route and had thrown everything into the auto mode. This is in line with their corporate strategies. Sony didn’t have a history with cameras and could start any way they wanted and Canon is known for abruptly changing directions. Nikon for whatever it’s worth rarely changes the way they do things and that’s why they have such dedicated followers.

The z9 af, once you learn how to set up a Nikon AF system is as good as anything in the market. Jan Wegener who is primarily a canon bird photographer on YouTube has done many videos showcasing this. So does Steve Perry.

Now as far as I know Jared Undone was never a Nikon shooter and coming to the system it’s easy to feel that the setup is unnecessary. Another YouTuber I have seen doing this is fro knows photo who used to be a Nikon shooter and knows how the Nikon af system works. But if you watch his reviews he almost always put his z9 on 3D tracking and complain about it not picking up the subject, which is again not how the af system works on a Nikon camera.