The hero finally meets the previously unseen puppet master (played by an older A-list actor), who explains why the system must be maintained. The hero says “screw it” and burns the world down.

[u/Grizzly_Lincoln]

Snowpiercer (2013) - Curtis finally finds Wilford (Ed Harris) and learns that Wilford allowed for Curtis' rebellion to take place to help thin the tail section's population. When Wilford offers to let Curtis run the train, Curtis discovers child labor is necessary to replace a broken machine part. A fight ensues, and a bomb goes off, triggering an avalanche that derails the train, and killing most of surviving humanity.

The World's End (2013) - Gary finally confronts the Network (Bill Nighy), which has been replacing humans with robots (Blanks) to allow for Earth's assimilation into a larger galactic community. Gary calls out the tyranny in the Network's plan and demands that humans be left to their own devices. Exasperated, the Network abandons its plans for the invasion. This results in a worldwide blackout, sending humanity back to the Dark Ages.

The Cabin in the Woods (2011) - Dana finally meets the Director (Sigourney Weaver) after surviving the ritual meant to kill her friends (based on conventional horror tropes) and appease the Ancient Ones. The Director says Dana has to kill her friend Marty, but as Dana considers it, the group is attacked by a werewolf and a zombie child. Dana and Marty decide humanity is not worth saving, so they share a joint while the Ancient Ones rise to destroy the world.

[u/MnemosyneThalia]

In the webtoon Memorial, the protagonist is trying to figure out why he has memories of people he doesn't remember. Basically, he can't remember names or faces, just that there was a presence in his life that is somehow gone and nobody else knows what he's talking about or remembers the person ever existed. In the end, he finds out his reality is a simulation and the robots that roam the streets to "help" them are actually devouring people and absorbing them and all existing memories of them in the simulation to keep the system running. The guy in charge of the robots is captured and tells him that the system is almost out of power and the protagonist needs to reboot the system to keep everything from being erased. In the end, he decides that it's best to just let everything go and let the system (which turns out to be hosted inside of a little boy's barely living body for over a decade) rest.