I don't see what moving it to 2222 does that turning off password authentication, requiring public key authentication disallowing remote root login, and fail2ba

I don't see what moving it to 2222 does that turning off password authentication, requiring public key authentication disallowing remote root login, and fail2banning repeated login attempts doesn't.. Is there a vulnerability in SSH or our asymmetric key cryptography that I don't know about(other than the one possibly introduced to the random number generator)? If there is, is the NSA less likely to use 2222 to knock on our door than 22? The only thing - the only thing - that moving it to 2222 does is reduce load avg due to brute force botnet attacks. And banning ips after 3 failed connection attempts should have a similar effect on the load avg. That is the only benefit. If you ask me that benefit isn't enough for me to give up the time spent typing -p 2222 every time i run the ssh command.