As per the current YTD,1,3,5,10,15,20 yr relative comparisons of BRK & SPY,
they are, +5.5%, -4.7%, +3.1%, -0.1%, -0.3%, -1.1%, & -0.1%

As always, somebody in the thread is required to point out that the S&P's price return has roughly tied Berkshire's only by getting more expensive, since Berkshire has risen in value more quickly.

For example: to make money, you have to sell stuff. It's an imperfect metric, but not useless--in the long run profits, therefore value, can't rise faster than sales do.

Berkshire real sales per share growth last 10 years: 5.50%/year, approximating value generation.
S&P sales: Up 1.66%/year. Add 1.88%/year average dividend yield to get real total value generation 3.54%/year, lagging Berkshire by 1.96%/year.

Berkshire real sales per share growth last 20 years: 6.93%/year, approximating value generation.
S&P sales: Up 1.61%/year. Add 1.96%/year average dividend yield to get real total value generation 3.57%/year, lagging Berkshire by 3.37%/year.

But a lot of things in the index have become a lot more expensive--higher price per unit value--so the market returns are remarkably close in this era.

And as the OP says, nothing actionable, just observations.
Maybe Berkshire's value growth will slow down to that of the index and the tie will continue. Or maybe the S&P 500 will stop getting more expensive and Berkshire might pull ahead. We'll see.

Jim


(all figures a couple of quarters old, since those are the ones I had handy)