It’s recommended you keep the default port because as soon as your IP is known it takes less than 5 minutes to scan every port for an ssh port
Fair point! I first thought that would be good, as it would discourage all those random connections. My guess is that they won't bother spending 5 minutes on each server, and instead just move on to the next when they fail. But then I realized that I don't really care about those anyway as they're not getting anywhere with their root:mypassword login attempts.