It turns out that if your suffering is spectacular enough, people will come save you. Maybe if we throw all the poor children of the world into caves people will start caring about them.
For me it seems as some sort of artefact of human cognition. (Mercilessly used by "last minute" opportunities by salesmen... and journalist.)
We're much better at dealing with time-bounded, localizable problems.
Stalin's quote about tragedies and statistics comes to mind.
There as Quote Investigator article on it, it is again a much older quote. https://quoteinvestigator.com/2010/05/21/death-statistic/
If this quality is order of magnitude lower than other less exciting solutions (e.g. access to medicine and education for kids from poor families), then we should be aware that what we pay for is not lives saved, but an emotional entertainment show.
Someone asked him why he didn't instead pour that energy into helping homeless people. His response was something to the effect that there were plenty of others helping people; his passion was the dogs. I believe he also turned the question around: what are you doing to help the homeless?
A few dozen cave divers can't do much to help the millions of impoverished children, but they used their skills to perform heroic and deadly feats to help 12 children and their coach, and inspired many around the world to ask themselves these types of questions.
Reducing that to a cost-benefit analysis vs some vague "but can't we spend that effort on the other lost kids?" question is both impossible and missing the point.
Cost or donation, can we expect the same for every child in need?
[0] http://www.humanosphere.org/world-politics/2014/10/united-st...
Helping every child in poverty requires a long term paced effort rather than a one time heroic one. As inspiring as this rescue was, it doesn't scale.