Worth watching is Justin Cormack's recent presentation on unikernels, LinuxKit, eBPF and databases such as SeaStar:
The Modern Operating System In 2018
The Modern Operating System In 2018
I know not a lot of people are using FreeBSD, but combined with OpenBSD I am pretty sure there are more than 1%.
Edit: Turns out it wasn't a lie.... at least in terms of Web Server usage... FreeBSD has less than 1%.
Sigh.
[1]: http://testinternetspeed.org/blog/half-of-all-internet-traff...
[2]: https://www.freebsdfoundation.org/testimonial/limelight-netw...