You're ignoring the fact that things are exponentially better and continue to improve under the Consensus. Cayde's plan working out because of dumb luck and the plot demanding it doesn't make it suddenly a good idea. You want to put all of humanity's fate in the hands of a single person. The greatest person to have ever lived isn't worthy of that responsibility. Humans are imperfect by nature, and for such a position nothing short of perfection is required. That goes doubly when the faction attempting to instate this person follows a ideology that reads like a paraphrasing of Benito Mussolini's personal description of fascism. So much so many people in the lore clans affectionately refer to the NM as "the spacenazis" because "vaguely fascist absolute dictatorship" is just too annoying to use with consistency.