Just the opposite. If your data is centralized, you can lose your data in any of these scenarios:

- A government or the storage company reads your files and shut downs your access to the data beacause of some policy (hello, Google Docs)
- The storage company changes the pricing terms on the fly asking you to pay more to keep accessing it (hello, Crahsplan), or simply shuts down due to bankruptcy
- A technical failure in the bridge or connection to the storage company
- A hacker access the storage company and destroys your data

In a de-centralized network like Sia this is impossible:
- Each particular host can't read your files, as it has access to incomplete fragments of it, and even if several of them were compromised, your data is encrypted
- A large number of hosts can go offline and you'll still have access to the data. Each file is distributed among 30 host, and you only need 10 of them to download the file. Hosts are spread worldwide