I would hope that world-stopping software (banks, critical infrastructure, healthcare, etc) have tests and all the things to prevent catastrophic error. For the rest of us, breaking things here and there in the name of moving faster is (anecdotally) more fun.
I think there exists something in between world-stopping as in healthcare (I want way more than just 'tests' there) and Facebook level (i.e. nobody really cares even though a lot of people will probably scream in "agony" when things don't work).
To maybe put it into examples:
World stopping: Traffic collision avoidance system (TCAS) has a bug that lets planes crash into each other.
Don't care: Not enough vegetarian meals made it onto the plane because of a bug in the meal reservation software.
In between: Thousands upon thousands of people get stranded in some airport for 3 days because of a bug in the route planning software.
This was an example within the airline industry but I'd say there are many more examples of where enough people depend on something for things that do objectively matter enough to warrant "good enough" software and software development practices that don't result in large-ish outages that then need to be fixed. Inconveniences I'll take because we all aren't perfect, even with testing.
most of healthcare software (that i have worked with) is really, really bad.
The fact that it mostly has no tests, or if it has tests they mainly test just the happy route.
They usually have lots of documentation, but it's not comprehensive and mostly just describes the happy paths, so when thing break you are out of luck. Also can't google anything since this are all closed source enterprise type software, so you are at the mercy of their support, that often also sucks.
And if you have to integrate with it, you often can't get the documentation, or tools to do it unless you are working for one of their VARs. And the VAR's are often even worse.
If you pick random 10 high school kids, get them into some code academy for a 6 months, and then have them develop an application, the ones that finish will probably be better than majority of health care software out there (for simple reason that they won't know enough to really screw up as bad.).
The only saving grace is, that its often written in Java so you can find workarounds in runtime (or inject stuff) if you really need to.
