Not that I have any skills in stock-picking whatsoever, but couldn't the recent lukewarm performance not also be an argument for BRK?

I mean their cash pile is also invested in money markets (so you get that), and the rest of the portfolio consists of quality companies where their (combined) valuation didn't explode in the last 1,5 years. So it's an opportunity to invest into something that might not be overheated.