Have you ever seen your sshd logs being clean without crowdsec or fail2ban while listening on 22/tcp with public IPv4?
At Skhron, all our customers benefit from our TCP tarpit system that detects global portscan:
Remarkably, this not only helps our customers but makes the entire Internet a bit more safe place - we automatically notify network owner about suspected device infection. This helps detect malware infection to cure it further.