Not at all. I used xhyve to run FreeBSD on my mac laptop, because I want to have a dev environment that matches production (except for performance wise). Mac OS's BSD userland is sort of similar to FreeBSD, but there's plenty of differences, and although it took a while to get xhyve working (and before it was available, I used virtualbox, which also took time to setup), the gains in being able to try something and know it will work on production, instead of trying something and having to try it again were worth it.

No more so that virtualizing one linux distro on another. Or running a Windows VM on Windows....

And let's be honest, while macOS has a lot of BSD in it, it isn't FreeBSD.

For example: Pre-APFS, imagine running any software with a custom data store using file system holes. Definitely something you'd rather do in a FreeBSD VM than on OS X directly.

I've been moving off Ubuntu in production since it adopted systemd, and a local FreeBSD VM is essential for developing & testing the provisioning and deploy scripts.