As opposed to centralized web applications, decentralized applications on the blockchain cannot orchestrate the reception of users documents, proposals for online editing of documents, or distribution of documents or media files to the user.
The most advanced initiative to solve this is IPFS, a decentralized file system using a peer to peer protocol derived from Bittorent. However, IPFS does not meet a key requirement of any file system, as sudden document disappearance independent from user action occurs. To avoid this, you have to pay a "pinning" service, through FileCoin for example.
While IPFS / FileCoin can store documents, it does not protect their privacy and cannot integrate document or media updates into smart contract logic.