I honestly don't know how long I will be able to practice medicine before deciding that I can build something better (as foolhardy a notion as that is).
It's very likely that something better already exists. The reason you use something terrible is because "better" does not result in adoption. Personal relationships, salespeople, and marketers drive adoption, not the quality of the actual product.
If you aren't positive that you are one or you haven't had this tested in the real world, then you aren't one.
It's not fair to patients to play fast and loose with their data, nor is it at all easy to develop and design usable software. It's not something you could do in your spare time while also working as a doctor. You'd most likely need to start a company and put together a team.
Not that I'm advocating this as a good thing. I only report a pattern that I've seen across a number of offices. I can also report that the nurses hate the computer system as much as the doctors, probably more.
(You would end up with the same thing)