No. of Recommendations: 0
Aside from the things Phil mentioned, for me, a big advantage of Berkshire in the last 18 years has been that the S&P 500 has been overvalued for the bulk of this period. This meant that most of my funds went towards buying Berkshire and none towards the index.
If the S&P 500 index was more undervalued than Berkshire, I may have invested more funds in an index fund representing it than in Berkshire. Hence, by having both, one gets the flexibility to choose where to invest, depending on valuation levels.
As Mr. Buffett has said, in the long term (say. next 20 years), the returns from both are likely to be very similar. But I still prefer whichever is more undervalued.
This.
I'm in the UK and I've had investments in, and invested more, in the FTSE 100 and FTSE 250 in the past decade or more. These investments have done worse than some things, and better than others. But the reason I'm content with them is that they seemed undervalued when I bought them, so hopefully fairly valued even if I was mistaken. The reasonable valuation makes it easier to expect an ok outcome even in "bad" circumstances, and perhaps a good outcome if things turn out well ... ;-)