Warran Buffet did indeed have a couple million USD when he was in his 30s, back 55 years ago when a couple of million were worth around 20 million in today's money. Measured in today's money he probably had 2 million at some point in his mid/late 20s. He became a billionaire at 50-something.
https://www.statista.com/statistics/378439/net-worth-of-warr...
https://data.bls.gov/cgi-bin/cpicalc.pl?cost1=2400000&year1=...