Some things I like about FreeBSD are its comprehensive documentation and its slow-but-steady pace of development. I find that it tends to have fewer features, but they are more solidly designed and less likely to change several times over a decade. Compare with Linux's rapid evolutions through hardware events frameworks (devfsd, hotplug, udev) or audio (alsa, oss, pulse) or systemd's ever-growing reach.

I feel I can keep up with FreeBSD, and have confidence that it won't change too much out from under me when I'm not looking.

That being said, it's not that different from a more stability-focused Linux distro like Debian.

Aside: here's an article about doing audio on FreeBSD, which also touches on some "why FreeBSD is nice in general" aspects, too: https://meka.rs/blog/2021/10/12/freebsd-audio/