It's being handled by algorithms and AI, not people. It requires only a relatively few people at the top of the largest hedge funds and financial institutions, all of whom are benefiting from it. Truth be told, they don't look at themselves as bad guys and in all honesty, they might not be. Aside from the unfortunate side effect of giving them the power to pick winners and losers, literally everyone benefits from a market that can't implode.
It's not like it isn't being said openly in certain corners of the Internet. Anyone who "breaks ranks" and says it will just be downvoted and ignored as a crank (as my simple comments here can attest). In the meantime, the indices will fluctuate and react to the news giving a veneer of authenticity, yet the march will move ever upward (as it has, manifestly, since the last "real" crash, 2008).
For those who think this is just bullshit, I would suggest that you read a fantastic book called Flash Boys and then contemplate that it was written in 2014. The author, Michael Lewis, had this to say, also, 11 years ago.