I think it is probably slightly quicker and is very intuitive, but I think the main advantage is that it just lets you share rich content a lot easier, so you can share movies, maps etc without knowing how to write code. The pain of uploading will not go away but if you say insert a picture, it will give you a choice of sources to select from of which Flickr is one as well as OneDrive, online images as well as images on your computer.
Here is the link if you want to try it:
https://sway.com/Enjoy