I had the idea that it was the snowball effect.
That there were no federal brakes in the past for putting the halt to a bad trend.
Now we have all sorts of brakes. Unemployment checks. Halt of trading if losses exceed so much. FDIC insurance. Interest rate control. Federal ability to cut taxes or spend stimulus money. Etc.
I'd appreciate your explaining your view of this as this is just my idea, not any formal knowledge.
But yes, there are a great many safety-nets in place now, which stem bank runs and market collapses, which were absent in the past. That's part of it.
Panics and Depressions are the final steps in a long line of bad things happening, from recessions turning downwards, to continual strikes, which in turn deflate the markets and with people out of work, purchases goes down which lead to mortgage defaults, etc.
The GREAT DEPRESSION was NOT caused by just the Crash of '29! Most of the world was already in a vast Depression ( fueled by the loses of WW I, the horrific Treaty of Versailles, and the devastating war reparations France demanded be paid by Germany and Austria and their allies.
And then, there were the unending coal and other strikes in England, with combined with the huge loss of life in WWI, followed by the devastating Spanish Flu, damned near ruined that economy.
Though most people think that America "roared" throughout the 1920's, the first 1/2 of that decade was pretty bleak here as well; economically speaking.
But, if you want a more detailed explanations of depressions, just ask, since I know that I'/ve somewhat veered off that, in this reply.