From the data in the article, the underperformance has really set in during the last 6 years. It’s a progressive decline. Pandemic market distortion maybe ?

From the data in the article, the underperformance has really set in during the last 6 years. It’s a progressive decline. Pandemic market distortion maybe ? Warren and Charlie just getting long in the tooth and slowing down ? Are the up-and-coming managers at BH (are there any ?) calling more of the shots and getting it wrong ?