I use both. I like both. But they feel very different.
Linux feels like a bazaar. You grab a kernel here, a package manager there, a init system from over there (usually systemd these days), and stitch it together. It’s powerful, chaotic, and moves fast.
FreeBSD feels like a cathedral (to borrow the classic metaphor). The OS is a complete, cohesive unit. The kernel and userland are developed together. ifconfig works the same way it did 20 years ago. ZFS is a first-class citizen, not an external module.
For servers, I prefer the cathedral. I want my storage system to be boring. I want my network stack to be predictable. That’s why I stick with FreeBSD for the core of my infrastructure.