IlikeMadison parent
I don't think using key-based authentication for SSH and enabling Fail2ban is necessary. Fail2ban is only useful if you keep password authentication. But I might be wrong.
I should check my SSH logs.
My intuition is that since the SSH server reports what auth methods are available, once a bot sees that password auth is disabled, they will disconnect and not try again.
But I also know that bots can be dumb.