The majority of the Internet’s routing and switching architecture is BSD based. Historically it had the most stable and performant network stack of all the OSs.
I used it extensively at one job in a previous life when I was a network appliance developer. It was rock solid and lightning fast. Tried it as a desktop at home and had a terrible experience.
The little differences in the Unix commands used to drive me nuts as well…
Fail2ban is not a static security policy.
It’s a dynamic firewall. It ties logs to time boxed firewall rules.
You could auto ban any source that hits robots.txt on a Web server for 1h for instance. I’ve heard AI data scrapers actually use that to target big data rather than respect web server requests.