I think people may be over estimating the liability angle. On the same token, good luck to some ambulance chasing scum bag lawyer trying to find your pizza delivery job a quarter century ago as well, let alone linking that to his junk lawsuit. Non event.

The real reason IMO is two fold. First, it tells your "life's story" which is a big deal to many HR departments, especially DL. You read a lot on the forums about "red flags" such as tickets or taking a certain amount of time to get your degree, etc, but it isn't really about any of that specifically. Your life's story is what puts everything like that into context.

The other reason is that its a great way to make sure you're detail oriented, or at least that you can be for a critically important known event like for (in most cases) the biggest job interview of your life. They also put a lot of emphasis on spelling and grammar, etc, not because they care so deeply about it on their off days, but because it helps show how seriously you are approaching the particular hugely important task at hand.

You'll need nice looking, shined shoes as well. They are big on that, mostly because they know that you know they are, so let's see how seriously you take this, etc.

A different major airline had (still has?) a hard on for the right color socks. Another made (still does?) you poop on a stick to get hired. The insane trivial pursuit knowledge tests many of the foreign airlines put you through blow away anything you'll ever see at a US airline selection process. Every place is different.

Its one of the more comprehensive apps in the US at least. But nothing they ask or expect is really that hard. Its just what they require, no big deal.