Until they land here and begin a dialogue with humans, I'm calling bullshit on all of it. There are no implications for humanity until then. Even if aliens are visited or have visited, so what?
We haven't seen any benefit from it unless inspiration for sci-fi films is a benefit, which I guess it is. So thanks for that, aliens. The film industry and its audiences have been a little more entertained over the years due to your shadowy presence. Sure, technological and medical advances along with the world-changing perspective of your known presence would alter the entirety of human existence, but Close Encounters of the Third Kind is a motherfucking classic, so it's a fair exchange.