Many applicants don't understand the process at all, nor what SS needs from them in order to approve them. By going through several steps and/or applications an applicant (generally) learns what is needed or an attorney or representative steps in and helps.

Many are advised to file prematurely to protect rights to backpay before they or their docs are clear about their long term prognosis. They may have been unable to work for a year or more but are still hopeful of recovery. When it becomes clear that they won't improve or they've even declined, their SSDI application is already mired in the long waiting process. (Some end up losing significant backpay anyway even if they eventually are awarded benefits.)

I've referred to the period of limbo when a person is dealing with denials as a game of chicken. Someone without access to resources that is disabled but borderline employable will try to work to eat and avoid becoming homeless. There are those that can't work regardless of how dire their financial situation. Others have WC or LTD income, savings, a spouse or extended family that support them temporarily. Will an ALJ inquire about these things? Perhaps--mine did. And a dire need letter can escalate the timeframe of a person's case.

As with everything SSI/SSDI related--it's complicated!