These charts aren't showing wealth, they're showing money. Money is not wealth.
For example, suppose you have a car that you paid $20K in cash for this year. That works out to about $10K 30 years ago (I think the Fed charts you showed are in inflation-adjusted dollars, though they don't say so). So as far as monetary vaue is concerned, you have the same net worth in your $20K car today as a person 30 years ago would have in a car that cost $10K then. (Or even a car that cost $20K then, if we aren't adjusting cost for inflation.)
Having owned cars over this entire time period, however, I can tell you that the wealth contained in that $20K car today is quite a bit greater than the wealth contained in a car that cost $10K 30 years ago. A $20K car today will be more reliable, get better gas mileage and give better average performance, have numerous safety features that didn't even exist 30 years ago, and have more bells and whistles in general. So in terms of wealth, I'm quite a bit more wealthy with $20K worth of car today than a person 30 years ago would be with the same inflation-adjusted monetary value of car.
And cars are actually a pretty poor example as compared with, say, computers or phones.