Subject: This stock
Let's say I believe Berkshire Hathaway is the solidest, best run, shrewdest company ever.
Doesn't most of its revenue come from heavily regulated businesses with capped profit margins? Why would it outperform a higher risk / higher reward collection of companies in the long run, which is what the US or world cap-weighted indices represent? You don't expect a utility ETF to outperform a healthcare ETF.
It might outperform one time based on relative valuation of the two. But BRK is already overvalued, if somewhat less so than SPY/VTI/VT.
tl;dr: number go up slower.