In my experience it is 2 major factors: fear and inertia. The risk of getting sued means that very few are willing to stick their heads out and do something innovative in this space, because any minor advantages (from the doctor’s point of view) gained from well-digitized medical records are outweighed by the enormous cost of even a single lawsuit.
The inertia comes about because we, as patients, don’t really care either way. We may gripe and moan about not having a digital record system, but riddle me this: there are likely many doctors with fully digitized systems nearby that you could go to. Switching to them instead of your GP would be a headache, but probably easier in the long run. Why don’t you? Is it purely because they have your records, or is it because the primary service that your GP gives you isn’t really about records at all.
I’m not saying it doesn’t impact patient care, but realistically until patients start switching doctors/hospitals because of their lack of digitization, there just isn’t enough incentive for anyone to care. There are a million projects, but change like this comes from patients, and currently there just isn’t enough demand for digital doctors.