NextSTEP which macOS is ultimately based on is indeed older than Linux (first release was 1989). But why does that matter? The commenter presumably said "Linux" for a reason, i.e. they want to use Linux specifically, not any UNIX-like OS.

Sure. But not everybody. That’s how I ended up on a Mac. I needed to develop for Linux servers and that just sucked on my windows laptop (I hear it’s better now?). So after dual booting fedora on my laptop for several months I got a MacBook and I’ve never looked back.

BSD is fun (not counting MacOS in the set there), but no, my Unix experiences have been universally legacy hardware oversubscribed and undermaintained. Not my favorite place to spend any time.