You probably have an innate desire for privacy. It shows when you close your curtains before bed and when you turn off your phone when a friend walks up. There are some things that you want to share only on your terms, if at all. Many of the cloud service you use promise privacy, and have written whole policies outlining how they go about preserving your privacy. However, when it comes to privacy, most businesses fall short of the kind of privacy that you innately desire in the physical world.

When your data lives on a datacenter run by a company, many people within that company have access to it by necessity. The engineers need access to manage the servers. The CEO often implicitly has access because they own the company, and by extension the servers and software running on the servers. Companies often have agreements with other companies to share data for advertising or support, which is hopefully disclosed in the Terms of Service you didn't read. Companies also have turnover, so people entering and leaving the company may have various amounts of access and varying degrees of adherence to user privacy policies.

Once you hand over your data, such as your family's pictures and documents, to a large enterprise, there is no telling what will happen to them. They have every reason to sell your data or metadata to third party data brokers or use it to train AI models. And if you ever want your data deleted, there's no good way to ensure that they actually comply. Even if the company itself is privacy-focused and tries to preserve your privacy, employee turnover is fast, and they can't ensure that their engineers always adhere to their policies. Unfortunately, typically it's profits over privacy, and this especially kicks in if the service they are providing is free or cheap. There is mature market for buying and selling your personal data that companies can lean on in order to keep running without having to charge you more. At best, it is only being used for targeted advertising, but once there is a well developed dataset about you available to the highest bidder, well... we haven't seen the worst yet.

Self-hosting platforms, such as our OYCS Iolite platform, offer true privacy by not giving your data to a company in the first place. All of your data lives on your home server, where not even the company who made the platform can get to it (assuming they didn't leave a backdoor, which is where some amount of trust is needed). You can control exactly who among your family and friends can access which apps and thus which sets of data, and know that none of it can be used against you without your consent.