One question that springs from the data quoted is what's the cause and what's the effect. Do people's net worth numbers go up in retirement because they "naturally" spend less, or do their spending numbers go down because they purposely restrict their spending to not run out of money?

If the latter, then saving more will provide a more comfortable retirement.

Also, leaving nothing for your kids isn't what I believe in. "Die with Zero" seems pretty selfish to me. My parents left me a bequest, and I plan on and look forward to leaving a larger one for each of our kids.