This may be feasible in Tim Berner-Lee’s vision of Solid and data pods.
I’d only do it if I control access to data, and can allow an auditable one-time no-copy access to get 0.X% off my mortgage.
But no handing over data to banks between banks / social media companies.
You enter the shop as a human being, and there's certain (human) rights that should come with that.
We're talking here about the right to get a copy of your own data, the right to be forgotten when you want to leave, the right to be informed about data breaches, and a right to agree to types of data processing.
Your analogy is "you enter a shop and cannot leave again, may be abused, and lose control."
I see a landscape of SaaS offers and connectors/data integrators between them that, inside an auditable analytics environment, is basically working in a plug-and-play manner. Databases are whatever happens in the back of these data governance environments. We load everything into a large mangaged data lake, and connectors are set up automatically.
I also see the scenario of radical data ownership not addressed, which may be a black swan event. Open-source competitors / legislation may enforce the use of e.g. data pods, as a digital identity storage with managed access right distribution. It's worth a though, what Tim Berner Lee's solid / inrupt would mean for the future of data storage systems. In this scenario, the transmission of personal data from pods needs to be optimised in a secure way.
I’d only do it if I control access to data, and can allow an auditable one-time no-copy access to get 0.X% off my mortgage. But no handing over data to banks between banks / social media companies.