This is bad advice. The idea that the essay a should demonstrate an applicant’s Ability To Overcome Adversity is one which refuses to die.
The essay is not a competition to see who had the most difficult time, with the “winners” being accepted. The essay isn’t a way to garner sympathy for one’s difficulties, nor is it a place to tell about one’s Triumph Against hardships.
The essay is a place to show AOs something about oneself that they cannot glean from the rest of the application and the LoRs. It is a place to showcase one’s best traits.
Focusing on the obstacles one has faced does the exact opposite. This makes the hardships the central focus of the essay, whereas the focus should be on the applicant. At the end of such an essay, the AO may know about the hardships, and know that the applicant may have overcome said hardships, but they will not know anything new about the applicant, and all the will have is a story about yet another kid who may have had some severe hardships, and who may have learned something from these hardships.
The AOs don’t want to learn something about the applicant’s life, they want to learn something about the applicant’s character. Specifically, they want to learn something about the character which will tell them whether the applicant is someone they would like to have at their college.