Why is this better than Orgmode? Orgmode is human readable, opens in any text editor, handles everything from bullet points to tables, and Github even has a Markdown-like renderer for Orgmode files.
Secondly, syncing is built in. Sure you could use git on your org mode file, but that’s requires effort.
Thirdly, this handles attachments and images.
Fourth, the user does not have to learn EMacs.
Fifth, it runs on phones.
So it does have advantages for some people. If your already an orgmode master, it may mean less for you.
2) You can put your org file in Dropbox, all the mobile clients support that too.
3) Org-mode probably does this too.
4) Granted :)
5) orgzly for Android, beorg for ios.
Not having to bother with Emacs is a huge plus.
These "questions" invariably come across as "this thing sucks because it's not the thing that I am used to".
It should also not be forgotten that the project linked has some features in addition to just note-taking and to-do lists, so it's definitely not directly comparable either.
The more likely pain-point is that on one device you have extra tools/configuration set up (e.g., org-latex), but these tools aren't available elsewhere (such as in orgzly). But I assume that this is a given for orgzly users: they probably don't expect they can do everything that org-mode enables in Emacs (like producing PDFs via LaTeX). They just want to do basic edits, and don't want to lose data when the document round-trips between Emacs and orgzly. (I don't use orgzly, but I assume that safe round-tripping is a feature...)
EDIT:
There is a Android App - https://github.com/orgzly/orgzly-android