Started watching the first episode but it seems pretty cringe so far... I think people asking why a train etc.. are kind of missing the point a bit - this is some cringy metaphor thing for NVQ film students, too dumb for A-Levels, at some local college to be like "omg the train represents society and our finite resources blah blah, it's sooo powerful, it's about class struggle blah blah"
I reckon a film is a much better format for this sort of thing than a drawn-out series - I haven't seen the film either but I did like The Platform (also on Netflix and also has the potential for "OMG it's about our society man, the rich at the top but, like, they were born at that level dude etc..")