Estonia (and now Ukraine) have worked on being able to do a "backup" of the country and a "restore" elsewhere if needed. (I am oversimplifying, but contingency plans have been part of the overall design that eID is a part of.) The UK doesn't have such designs and contingencies in place. The private sector is no better, every year there are major security breaches. It is premature to stick Digital ID onto a rickety network of badly secured databases.