This all sounds reasonable. Meta question here. Is it necessary to say "I am not a lawyer...if you need legal advice, retain a lawyer."? Is that statement real

This all sounds reasonable. Meta question here. Is it necessary to say "I am not a lawyer...if you need legal advice, retain a lawyer."? Is that statement really legally protecting you? Is it intended to encourage the reader to take you less seriously? I'm having trouble not seeing this statement as a cargo cult prefix/postfix to commenting on legal issues, and if it's not really necessary, it seems more tasteful to me to leave it out.