You should see "computing". Resizing a window in Windows has become a lost battle. Working with files on Android is a torture. I really hope that "medical practices" will not "evolve", like "computing" has.
In an ideal world where every medical record is digitized it would be possible to discover long term causal effects that nowadays we don't know because running long term studies is hard, costly, and in a world where publishing is everything they don't lend to it. So we explored and confirmed only the most obvious long term cause-effect connections.
Therefore, it would enable prevention of some diseases for which we, nowadays, can only have a reactive MO.
Companies sell the data to ad companies, before any meaningful research can be done.