What this article is missing is the distribution of this growth in wealth by economic status. Distribution by economic position is not in the FRED tables. Because, as is well documented, since 1975 nearly all growth in American wealth was achieved by the top wealthiest 5% of Americans, with most of that going to the top 1%. The bottom 99% received almost no growth in real wealth.
There is no reason to believe the most recent growth would be more evenly distributed than it has been the last 4 1/2 decades. In fact, it is likely worse. First, the general trend toward increasing income and wealth inequality has not changed. A recent analysis by the Rand Corporation estimates that if income was distributed in the same general rate as in 1975, about $50 trillion (yes, with a T) is now in the accounts of the 1% that would otherwise have been part of the wealth of the 99% of Americans. Second, one of the largest contibutors to after-tax wealth is tax cuts. And the 2018 tax cuts heavily favored the 1%, both in the rates that were cut and, given the massive wealth disparity to start, by far the total wealth gained.
So it is likely that this "growth" in wealth is limited to the very richest of the rich and does not include 99% of Americans. And it is temporary, because it was also fueled by the free money stimulus of the Fed, which mostly goes to the financial sector, and the stimulus package passed by Congress, which we are finding out more and more was taken advantage of by the rich as well. This has all resulted in a massive increase in the national debt, which has to be paid back eventually. I leave it the reader to guess which economic strata are going to have to sacrifice to pay back the debt.
So this "interesting" growth in total wealth during the pandemic is neither as unexpected as it seems at first, nor is it relevant in any meaningful way for the vast majority of Americans.