

We are presently on course for the 二分之一 timeline.
In that one, some aliens arrive in the 2030s. They noticed our cruelty and debauchery, and informed us that our extinction will come at our own hands if we continue. The elites of the world laugh this off, and lock the aliens up on some island so their autotroph nature can be studied instead.
Fast forward to the 2060s. COVID has returned, killing more people than ever before. This is on top of the ongoing nuclear civil war in the US, and nuclear devastation elsewhere. With most of the elites dead or hiding in a bunker, many of the people who survived asked the aliens for help. The aliens agreed.
This resulted in a conflict between our present world and a world that appears to be a mix between Fahrenheit 451 and Brave New World, supported by the alien followers. The aliens are genuinely, fully willing to give you free healthcare, a long life (people supporting the aliens can live for 200 years), and a life free of worry or suffering (an alien will replace most of your organs when you join, allowing the alien to handle many of your basic needs, like food). The only thing the alien faction asks for in exchange is tossing out human culture - your favorite books, movies, games, etc are all gone, replaced by materials accepted by the aliens.
The alien faction ultimately won by the turn of the 22nd century. The surviving elites tried their hardest to get rid of them, but failed. Instead, the aliens continued to rule the human race unopposed until the close of the 27th century.
I’ve had lots of encounters with those Christian crazies. They tried to convert me twice.