Yes, you are right that Mukesh Ambani has taken over and become wealthier than Warren Buffett although you can argue that it is more of paper wealth. As per the latest rankings by Forbes, Mukesh Ambani is worth $70 billion while Warren Buffet is worth $69 billion. So the gap is very small but overtaking Buffett in the midst of the pandemic is surely creditable.

To a large extent this can be attributed to the Reliance price appreciation effect. Consider these numbers. The 120% rally in RIL in a little over 100 days has helped Ambani family, owning 50% of RIL, to overtake Buffett. Reliance has been a 4-bagger since December 2016, when Jio was first launched and the wealth was largely driven by Jio and digital forays.

But there were also some bad investment decisions by Buffett. His airline bets were not wrong but timing was bad. Airlines took a big hit due to the embargo on international flying. Eventually, Buffett exited airline stocks at huge losses. Of course, his aversion to technology stocks also did not help. Apple was too late in the day and IBM went really wrong.