BSDs may not have a significant presence on desktops, but they're well known in the networking world for their reliability. They also were the foundation used to build OSes for specific applications. OpnSense and XigmaNAS, for example, are two excellent FreeBSD based applications aimed at firewalling/security and NAS/services.
Sorta. The original firewall distribution derived from FreeBSD was m0n0wall, then its development stopped and it was forked into pfSense, then pfSense was forked into OPNSense and the two projects are now complete separate things.
About which one to use, Manuel Kasper, the original m0n0wall author, encourages to use and contribute to OPNSense, which is also the one I would personally choose after [0] happened.
https://opnsense.org/
https://xigmanas.com/xnaswp/