come by definition. The reason for 1929's depression is gold based currency system, and we do not have it any more. Also we are lucky to have 1987 finance crisis already happened as our guide for this crisis. I am not saying that 1987 is the same in nature and scale as this time, but they are very similar.
My opinion is that liquidity crisis is easy to solve, just print more dollars, but inflation problem and resource supply problem are hard to solve.