when pulumi knows about the hierarchy of resource creation, why don't it show up in the hierarchy as well in the plan? it would be awesome to see resources dependency as pulumi internally know visually in the shell

So as you noticed Pulumi differentiates between the ordering relationship and the dependency relationship. The ordering is like parent -> child and it is one:many and that's what you see when you run a preview. But dependency is many:one so it must be different, and is obviously a bit harder to draw in console. You can output that tree with with the “pulumi stack graph” command. It can output a .dot file

oh thanks :-)

Well it's not the same kind of tree. I'd love to see an example of a big many:one tree like that being drawn in console such that it is legible and useful. It can't really be drawn like the parent:child tree, because a node at the bottom of the tree could be touching a node at the top directly if it depends on some property of it.