Also consider the difference in voting rights. Voting rights at berkshire require one to literally be rich. Funny that SNAP got shunned by S&P and literally was the genesis for a new rule [1] for excluding new stocks with split share classes yet BRK, GOOG, FB, CMCS, NWS, etc. can still exist in the index. Heck, companies like F & BF have separate voting shares to give families voting rights.

[1] https://www.cnbc.com/2017/08/01/snapchat-excluded-from-sp-50...