Buying is effectively a solved problem, the circuits will be de-facto nationalised across Europe very soon if they're not already, as an inevitable outcome of going cashless (which COVID19 accelerated). What will likely never be nationalised is credit, that's where VISA/MSC/AMEX/MBNA will hang around for the foreseeable - unless some of the "new banks" like Revolut and Starling explode on a level where they can afford to start their own thing.