If that was always true, there would not be an option to do it...Research the differences between phase detection and contrast detection to achieve focusing. You will find that ANY lenses used on mirrorless bodies do not need focus tuning if the mirrorless body uses phase detection focusing.
That's about the best explanation of the two AF methods and why AF Fine tune may be needed in any camera using PDAF.According to Reikan FoCal there is utility in performing AF Fine Tune. Scroll down a ways on this 2018 blog post about the Z 7 to read the details. It has to do with whether the lens actually moves the amount the camera instructed, especially when using Phase Detect Auto Focus (PDAF) where the sensor measures both mangitude and direction.
They make the focus calibration software so I think they’d be pretty versed in the subject. I use their software for my D850. I have not used it for the Z7.That's about the best explanation of the two AF methods and why AF Fine tune may be needed in any camera using PDAF.