IME the integration with FreeBSD and ZFS just works better than BTRFS and linux distors, and I've read far too many reports about data loss with BTRFS to trust it.
But I definitely believe that everything you can do on FreeBSD, you can also do on Linux. For me it's the complete package though that comes with FreeBSD, and everything being documented in the man pages and the handbook.
Sure, but ZFS is much better integrated into FreeBSD. It supports ZFS on root with boot environments out of the box.
And when running a Samba server, it's helpful that FreeBSD supports NFSv4 ACLs when sitting between ZFS and SMB clients; on Linux, Samba has to hack around the lack of NFSv4 ACL support by stashing them in xattrs.
You can arguably get even better ZFS and SMB integration with an Illumos distribution, but for me FreeBSD hits the sweet spot between being nice to use and having the programs I need in its package library.
But on Linux you need to load external modules. Before upgrading or changing kernels you need to check if ZFS supports it. Specially bad in rolling distros.