But can we count on people to candidly self-report failure, even when it's optional? In either anecdotes or a research journal?

I don't believe so.

Aside: There's better exceptions to my original post, e.g. in US we release outcome statistics at schools.

- https://www2.ed.gov/rschstat/catalog/student-outcomes.html (outcomes)

- https://studentaid.ed.gov/sa/about/data-center/student/portf... (loans)

So we even get data in some cases. But experiences in many things like dating and job searching isn't mandatory for everyone to report. And sometimes the most impactful things don't fit into Pandas tables well :)