‘Record high’ is a meaningless stat by itself. The population is at a record high too, so everything else of this type will naturally follow. There are more billionaires than ever in the USA, as well as more millionaires than ever. There are more cars than ever. There is more money sloshing around than ever.
The rate of increase of credit card debt is unprecedented in the recent era. Far far more than the rate of increase in the population. This is a trend that has been developing for over a year, and it reveals the weakness of the metric of “consumer spending” as a sign of economic health. But you are right, the number of millionaires and billionaires are irrelevant to evaluating the state of the economy.