There is already one PDS provider in the UK, Mydex CIC. It seems to be active mainly in the health sector.
But the new approach can only become infrastructure, and reach national scale, if users are given a choice between different PDS providers, and are assured of interoperability and account portabiity between them.
When this need for choice between providers is accepted, and a route to national scale is set out, we expect that the retail banks will begin to offer PDSs. The service can be seen as complementary to the provision of banking services, akin to safety-deposit boxes in the physical world.
It’s also possible that the mobile network operators offer PDSs. And Big-Tech (i.e. Google, Microsoft, Facebook, Apple) may decide to participate, but would have to accept external regulation, something they have long been unwilling to consider.