Perhaps, but I think a million USD in total savings is a lot of money, too, and I do not think the majority has that amount in total savings. Are there any statistics on this?
There's also a difference between retirement savings and net worth. I'd guess there was a jump in "house poor" millionaires over the last few years.
The Fed has a Survey of Consumer Finances which can graph net worth broken down by perentile. You're right that even $1M net worth is not the majority, but top 25%ile:
https://www.federalreserve.gov/econres/scfindex.htm?mod=arti...
https://www.federalreserve.gov/econres/scf/dataviz/scf/chart...
Probably more millionaires in the last few years with inflation though.
This is all US-centric; the author, Richard, is in Japan; I'm not sure how net worth, savings, retirement, or taxes are in Japan.