The telephone is only useful if there is more than one. Otherwise, you simple have a piece of art or a glorified paper weight. When there are multiple phones you can call someone else. However, it doesn’t mean they will pick up. Even if they are near their phone, they can choose to ignore it.
When we talk about data portability, we tend to focus on the ability of a person to take the data we have about them with them to another organisation. This is likely because the ability currently rarely exists. In fact, it is rare for someone to get access to the data we have, let alone take it with them. (Similar to the ability to make a phone call.)
However, for the ‘ported’ data to be useful, another organisation would need to be able to use it. But also ACCEPT it. In essence, they would have to trust the data and the organisation that issued it. They would have to ‘pick up the phone’.
With today’s technology, it is relatively easy to show the ‘ported’ data has not been tampered with. And that it was the organisation it says it was that created the data. This is technical challenge that can be resolved. However, trust is completely different. For portability to work, we not only need to trust the organisation (the brand) that captured the data, but we also need to trust the local outlet of said organisation.
This is one of the roles of governance. Governance needs to address both the technical and the human. Otherwise there will be lots of phone ringing and no one picking up.