This or similar software is basically required is you have an SSH server accessible over the internet

Don’t make the mistake I did and assume that your server is too small or inconsequential to get hacked - a hacking attempt is a matter of “if” not when, but turning off password Auth and adding fail2ban will get you locked up tight

These days I would recommend CrowdSec over fail2ban.

Old software that can actually be superceded by some newer tech if someone feels like doing so.

Easy to use, lots of documentation. 10/10