Doesn't make much sense to refer to OneNote here, although both applications serve a similar purpose.
But as Evernote is based on a database (afaik), OneNote is based on file and folder structures on the storage level (even when the notebooks are stored on OneDrive, where the OneNote files are hidden except for a URL link file). In the original OneNote format notebooks are simple folders in the file system, sections are files (with the .ONE extension) that hold all pages and subpages in an object centered format based on XML. So it's natural for OneNote to use a hierachy, but lacks 1-to-n relations. A note(page) has to be in exact one section. If you want to sort a chocolate pie recipe under "pies" as well as unter "sweets", in OneNote you would have to create two sections and put copies of the recipe note in them. All changes would have to be done to both notes separately. In Evernote you simply add both tags to one note. That's the beauty of relational databases. Yes, OneNote does have sort of tags, too. But those are merely an optical marker of certain objects (like paragraphs or pictures) whith almost no way to use them as a filter or for detailied searches.
I am not trying to bash OneNote here (in fact, I have been a OneNote MVP for several years, and still very active OneNote user), I am just trying to point out that the underlying data structure/model of both programs are very different and I suppose it would be very difficult, if not impossible, to just transfer organisational concepts from one to the other.
