This is an opinion that I've often read, but that does not match my limited experience. The difference in quality between BSDs and Linux is not clear. I've found outdated documentation on both sides, though BSDs mitigate this by being more stable (i.e. less innovative, if you prefer looking at the dark side).

For instance, a blog post was recently describing struggles with the NetBSD installer. It complained that the documentation chapter about installation was 7 years old, and about obsolete releases of the OS and its installer. https://eerielinux.wordpress.com/2025/05/31/installing-bsd-i...

Another example, this time with FreeBSD. The documentation still has a section about floppy disks, and the chapter about "Linux Binary Compatibility" is for Linux 3, about 10 years ago. Hard to tell if these pages are still valid.