What is then the torture of all the Humanity, against the super happy Felix with 3^^^3 pyramids. Nothing. By the same line of reasoning.

It's hedonistic total-utilitarianism vs preference based consequentialism. That's a big difference. Not only would the 'sequence' you reject not advocate preferring to torture humanity for the sake of making Felix superhappy, even in the absence of negative externalities it would still consider that sort of 'happiness' production a bad thing even for Felix.