If you’re a regular internet user the Personal Data Storage paradigm won’t move your data from the cloud to your personal computer. Most people will still rely on an institutional cloud service, but instead of data-banking with a shareholder-controlled corporation people’s data can be entrusted to the equivalent of member-owned credit unions for data storage.
it does. you need to choose the software. you need to install the software. you need to update the software, and be prepared to deal with a bad update. you need to keep backups so that you can restore your files when disaster happens, and you need to know how to make a proper backup (have all the data, also backup the permissions, databases need special care, …) and how to restore it.