I have no dog in this fight (I use both Linux and macOS as daily drivers) but it could be argued that macOS has more of a claim to be Unix than Linux since the foundation of macOS comes from NeXTSTEP and FreeBSD whose codebases both ultimately descend from the original Bell Labs Unix, whereas Linux started life completely independently.

I'd argue that Linux is more Unixy than macOS in terms of philosophy though, I remember reading that Dennis Ritchie considered Linux as much of a Unix as the other offerings on the market at the time which were the BSDs and commercial Unix variants; his opinion is obviously worth thousands of mine!

OSx is also Unix certified by the open group, along with hp-ux and aix.

https://www.opengroup.org/openbrand/register/

There is a Linux distro in that list, too: Huawei's EulerOS, based on CentOS.