Everybody else has done a great job at explaining why this plan had a very low chance of working, but there's one big reason why it would be a bad idea even if it had a half decent chance of working: it's completely binary — It either works, and you rescue everybody, or doesn't, and everybody dies. There's precious little room in between.
The plan they enacted, even if it might have had a lower chance of success (and I don't know that it did), was much more resilient.
One of the really important things the article explores in detail (but never calls out explicitly) is how many backups and fallbacks there were. Air tanks spread across the whole cave, multiple support stations with extra people. There were many opportunities to adjust to changing conditions. Even if getting one kid out went wrong, attempts at rescuing the others were mostly independent. All of this adds up to a pretty damn good chance of at least partial success.
The plan they enacted, even if it might have had a lower chance of success (and I don't know that it did), was much more resilient.
One of the really important things the article explores in detail (but never calls out explicitly) is how many backups and fallbacks there were. Air tanks spread across the whole cave, multiple support stations with extra people. There were many opportunities to adjust to changing conditions. Even if getting one kid out went wrong, attempts at rescuing the others were mostly independent. All of this adds up to a pretty damn good chance of at least partial success.