Don't most people use something FreeBSD based for production use ? I was under the impression OpenBSD was more used for testing and security research.

For personal devices I'm not sure why anyone would run a BSD in the first place

Easy to install and upgrade, sane defaults, good documentation, lack of waffleburgers of complexity, so I'm not sure why anyone wouldn't run OpenBSD in the first place. Granted I put Windows in the unusable bin and it's been there for decades now and sounds like it is getting worse, what passes for Mac OS X these days is not so good given that you have to disable some security thing to properly kill the annoying and disruptive notification system, among other annoyances still being fueded with, and I gave up on Linux after trying to support that waffleburger in production for a year or two.

OpenBSD is absolutely a research OS and that's okay.

My understanding is that Netflix used to use FreeBSD to serve video, but I read somewhere they're no longer using it. Not sure how true that is.

Some game consoles like the Playstation run a modified FreeBSD as their OS.