PS4 trailer

[Noata]

You are ignoring compression, and storage space is cheap. Bandwidth is the costliest.

That's not how it works. I work in a datacenter. Compression is impossible, a file compressed can be used unless the data your compressing needs to be referenced or updated(each time it did would require an un-compress then re-compress meaning you need to save space for the files expansion). so compression is a no go. plus the additional IO and transfer of data to read all this data that updates if you move any icon, switch any item and so on would be bad practice. for example. websites cache stuff locally to a browser to stop the front end from having to constantly query the backend database.
so to list a few flaws in storing the data on a server in a data center.
-additional monthly cost from data center to "store" data.
-additional IO that would require additional monthly fees to provide from data center.
-new design to support the amount of database queries to all clients simultaneously
#Data centers charge by the GB of space. getting 10PB would likely cost more per month then most of you make in a year.

Data center storage is not cheap... this is not paying 30 dollars for a 1TB drive. Server storage is on a whole different level and is not cheap.

Not saying its not possible. just this is done by design and not later. it could call for recoded server structure. the easiest way would be to limit what is saved. Like TERA who keep a small config file that gets pulled down locally and updated when modified and sent to server. though what they save is very limited.