The one really nice feature that makes Office 365 worth it for me is that you get 1 TB of space on OneDrive. And unlike iCloud or many other cloud services, OneDrive supports versioning of files, meaning if you change a file and save it, you can always retrieve past versions of that file. Also, if you delete a file, it can be retrieved for up to 30 days.
Those features make it perfect for storing important files online without having to worry about backing them up on a daily basis.
Considering the price of Office 365 and the amount of OneDrive space they give you compared to other cloud services, I consider the Word/Excel/Powerpoint access a free extra bonus.