These slasher zombiesques, as it turned out, traveled not with the standard-issue random lumbering, slovenly, slobbering pack,
However, instead of spending the movie as they should have, chasing after their human prey, who likewise should have spent the movie trying to avoid their zombie predators - these designer movie-zombie-types made themselves at home, barked orders and waved their scissors around at their terrified hosts, who often seemed not quite sure what they were supposed to be doing, but who definitely lacked the wherewithal to run out to the kitchen drawer and grab some scissors of their own.
I guess it was full of metaphors and symbolism, if you feel like calling all the ins, outs, and what-have-yous going on in the movie metaphors and symbolism. Of course if you want to you can find metaphors and symbolism in every movie ever made, good, bad, or indifferent.
So I don't know, maybe "Us" did have metaphors and symbolism, but it lacked tension, except for what was created by the plinky, scary-sounding music. It lacked any real scares, unless you count gore. It lacked logic, and even a movie about look-alike zombiesques requires logic within the zombie-world frame of reference. It was just one sloppy, disconnected, indecipherable scene plopped down after another. Until it got downright dumb. Which is actually okay for a movie to be, as long as it's an engaging ride. Which, for me, "Us" wasn't.