Earlier quoted context omitted.
Google &c already own most people's data. This makes it possible for it to be portable and network based.
Not so. Google most of your data. If you have your tax records on gdrive, google so far cannot target ads based on that content (i can't say forsure if you attach your tax form in gmail nowadays) With SOLID any site can simply say "we need your tax records to prove you're a human or combat fraud whatever". SOLID and all other not-solutions like it make your consent as useless as android app permissions. Accept a huge…
This is not true. But there are human factors issues to solve. Personal AI will help.
Most of what google &c possess is inference and real-time metadata, which is the real dark magic. Giving people precise control over their identity and information via standards will be a huge gain, but it's not an easy task.