Is the Underland Full of Sad Earthmen an Allegory for Something in This World?

Is the underland full of sad earthmen an allegory for something in this world? Or is it e kind of depiction of evil in general and the power that evil can have over people? Do you think when puddle glum says, there are no accidents. Our guide is aslan, that lewis is espousing some sort of determinism? Is he just reminding people that god is ultimately in charge, even if it doesn't look like that? I don't think lewis as into determinism. I think lewish is into something else, which is, whatever happens can be made to be useful and good.