If the population on earth could be of value to me as an etheric energy resource / chattle / slave labour, I wouldn't want any of them to really understand what's actually happening.
I would build religions instilled in the masses. I would lace it with traces of advanced technology so that its followers believe it must have special meaning. I would predict avenues where others might try to make themselves known and liberate the masses. In just about each religion I would instill the idea that such visitors would be demons and attribute consorting with them to be an evil so grave that it deserves the ultimate punishments: eternal torment / extinguishment of their immortal essence. I would keep several competing massive religions, so as to keep the maze elaborate. All of the mazes lead to never ending circles or dead ends without explanation. I would feed the sciences to the point that little seems hidden, but again the true tools of science: perspective from outside the body, I would relegate to lunacy at best, and at worst, in the major religions, once again mark that as sorcery / evil.
Now some little tribes and traces of alternate theories would occasionally survive. For those I would build large tapestries of channels and concepts I deem beyond everyone's wit. If I can't burn them all in a genocide.
So as whenever any animal arrives in the pasture, the sheep see only another wolf, no matter what its shape. And the only source remotely trustworthy is the shepherd within. And in a day when someone powerful enough comes along, insisting I give them free will, I can gladly lift the veil. Their endless days of chicanery and confusion will leave this new world of theirs, barren of deception, so foreboding and mixed to them, they will desperately scream for a remedy. They will beg me to get put back in the dark and behind the fences. Should they have chosen their own elected representatives, it won't really matter. Nothing is known any longer as a rightful election. No one is known any longer as an honest official.
The only real wisdom available to them, from that point, is to question if a creator and governor of the universe would be so cruel, to produce or allow an eternal torment or true extinguishment. That such a cruel thing be even possible. And even then, those questioning such a reality would be left comparing a sea of evidence that would take them lifetimes to make sense of.
They would be utterly stupid in just the ways I want them to be. And I have to wonder from this perspective, it would seem bleak that they should have any hope at all of escaping for a very very long time.