There are 4 primary reasons:


  1. Ease of access from OUTSIDE the corporate network or from Macs
  2. Collaborative editing (multiple people editing files at the same time)
  3. Constant version history - Microsoft turned off AutoSaving a number of years ago unless you're using OneDrive or SharePoint.  How helpful of them.....
  4. Access from phones/tablets/mobile devices
  5. Eliminating the cost of managing/maintaining on premises servers (in some cases)


All of these are features that Google Docs has had for years, so Microsoft is catching up.


There are a few downsides to this solution that you should be aware of, however:


  1. Security - it's harder to maintain control over the data when your users can access it from offsite / any computer.  We can add restrictions to only allow the data to be accessedfrom 
  2. Licensing - all users that need to access SharePoint now have to have at least a Microsoft Business Basic license (which at the time of this writing is $6/month with annual commitment)
  3. Availability - Microsoft has a lot invested in making sure your data stays secure and available, so we're not as worried about data loss as we are Internet outages making files unavailable.  There are a couple of workarounds however:
    1. If you right-click a file, you can tell OneDrive to "Always make this file available", and it will store a local copy on your machine for access even if you're offline.
    2. Even if your traditional Internet access is unavailable, you can often tether with a mobile phone and access the files
    3. You can also just access the files directly on the mobile device.