This may be an unexpected feature, but one can move file by changing name to include path, for example to move a file one folder higher:

I was about to suggest renaming the label from "Rename" to "Move/Rename", but unfortunately "Rename" is disabled when more than one file is selected:

TL;DR

We seem to be missing UI for "moving multiple files": right now only way to do it is via repeated drag&drop. One per each dir level, which makes it extremely painful if you want move /from/this/deep/dir/ to /some/other/one/.