The users of the sub-par app are captive, the hospital or insurance company is mandating it, and neither the doctor nor patients are free to choose a competing app.

If you create a technically better app for the users, people still won't be able to use it unless you also are chosen by those higher up, and since there's likely already a strong existing relationship between the executives at the existing company and at the medical compan(ies), that means creating a competitor also will require building a lot of social capital with the decision makers, taking them to dinner and on golf trips, and so on.

It will take years of your life, millions of dollars (since a 1-man company will never be seen as legitimate enough to provide a medical app, you'll need a large company with many employees), and the chance of success is minimal.

I don't see how this is an "appropriate" response to a bad app.

I was just thinking of a better front end for the same API that trifticon mentionned. Still a lot of work of course, but may not require as many approvals.

I wish we lived in a world where all these APIs were open, regulated, and everybody could compete on the implementation on both sides... One day, if capitalism survive technofeudalism...

Even avoiding the problems with getting a foothold into this space any start up that tried to do the right thing would get bought up by someone else and enshitified until it was just as bad if not worse. There's more money to be made by screwing over the public than by not screwing them and our entire system is centered around making the most money at any cost and placing money over every other concern.