accessible anywhere you have an internet connection.
And that is where the concept fails every time. While we do take for granted that we have internet everywhere....what happens if we don't. Lets say there is a natural disaster and the lines are severed. Well now any and all vital information you may need is gone.
I don't think everything will go cloud ever for this exact reason.
I like to think of cloud much like when I worked in editing. An edit RAID is for disposable media only. If it has a backup somewhere or you don't care about losing it it is great because it is faster and more convenient. But you should NEVER store anything important, like a project, on the RAID....because if it goes down you lose everything.
This is how I feel about cloud based storage systems...they are for disposable media. Music, movies, ebooks, anything that you consume and could live without. Anything you have created however, photos, docs, contacts, etc should not be stored on a cloud as a primary storage....it is fine as backup, especially if its setup as redundant to a local source like an SD card or even a computer....but NEVER as a primary storage...because you may lose it someday.
I've been backing up data to my gmail account for almost a decade now...that was the first cloud storage I ever used....but I know that one day gmail will cease to exist or will not be available...so I have to remember none of that info is permanent. If I do an invoice in google docs I always make sure I save a copy on my local hard drive. My contacts are synced across my local computer, my local iPad, my phone and my gmail account.....so the redundancy there is pretty secure, short of a massive EMP.