FreeBSD is a nice, solid piece of Shaker furniture. It's simple, elegant, and done "the right way," meticulously planned out. There are no extraneous seams.

GNU/Linux is an amalgamation of 2-3 of the highest quality IKEA sets. It's more up-to-date, with more bells and whistles. If you don't like one component from one set, you can (with enough elbow grease and fuckery) replace it with the analogous component from another set. However, there are bespoke seams everywhere, and the theoretical flexibility is often more trouble than its worth (just try using a mainstream distro but replacing systemd, for example). Also, the documentation is sometimes out of date, causing things to fail in utterly inexplicable ways, forcing you to resort to online forums and mailing lists.

FreeBSD has somewhat fewer features, and doesn't work as well with the latest hardware. But the things that are supported largely Just Work(tm). It is, by and large, just less hassle to run FreeBSD and you don't have to tinker as much.