When Tim Berners-Lee invented the Worldwide Web he made it free and open source, so others could build upon it. In the early days it was quite open with individuals sharing knowledge through blogging and collectively building knowledge with wikis, the largest being Wikipedia. But as more people joined the web two things happened.
Commercial forces found ways to monetize their audiences. They built attractive ways for people to get online as easily as possible. They even hired psychologists and anthropologists to study human behaviour and then devised ways to manipulate it. They aggregated this data and used it to sell targeted advertising. All the giants on the internet use targeted advertising — Amazon, Google, and especially Facebook.
Meanwhile, many people found blogs to be too much work, and wikis to be confusing. They wanted convenience so that they could connect with their grandchildren. Facebook was the solution. It was convenient and allowed easy sharing and connections. But convenience, like a principle, has a cost.