I definitely saw the twist coming but it didn’t stop my enjoyment of the overall movie. You don’t have your character suddenly meet their doppelganger and then just escape instantly. There had to be a switch.
I think the reason why the film is so successful is that it can be read in so many different ways. Whether it’s the idea of coming to terms with a troubled past or even just the nature of society, where for some to prosper, others have to be suffer.
I think at the core of the movie, there is this big central question of nature versus nurture, which frequently comes up in discussing whether people are inherently good or evil. Because it is a horror movie, initially the split between evil and good is fairly obvious, but it becomes more complicated. Us expresses the concept of nature vs nurture on the individual level, especially focused within Red and Adelaide, how it extends to her family and finally all of society in genral - with Red/Adelaide being the lynchpin that turns everything upside down.
The tethered live underground and are initially depicted as evil and not possessing a soul but, I don’t think that’s the case, because really they are denied all the liberties the above ground dwellers enjoy and take for granted. Their life is lived underground, on one side of the corridor they sleep in bunks, on the other they eat live rabbits and inbetween are vaguely steered by their doppelgangers above.
Adelaide pretty much learned to fit into the world above after the switch. She maybe wasn’t as good a dancer ever again but for the most part she’s a normal human being, she wants to protect her kids and even if she has been aware of the awful truth lurking underground she does feel remorse for her other half. I think the really nice touch was the way she comforted her dying doppleganger daughter. A version of her daughter she effectively abandoned. On the flipside, Red was driven by vengeance, her voice turned hoarse as she was literally starved in a mental capacity for all those years.[/spoiler]
I think the end twist comes off as a littly flippant. The implication that Adelaide is perhaps not as virtuous as the strong female horror protagonist would imply. There is hope for us all, so long as we’re aware of those who do suffer when others prosper. I guess that’s the sugarcoated message I got from the film but it’s so rich in meaning.