A little something I threw together showing who controls what. Even if Vanguard or Blackrock don't have the majority shares, they have the majority shares in the corporation that does... Btw Vanguard Group has the majority shares of Blackrock...
You can do your own digging by searching Yahoo Finance. https://finance.yahoo.com/quote/PFE/holders?p=PFE
That's some nice digging. Insane how much three companies control, however it's easy to grasp when info is organized effectively.
Forgot the major credit card companies
Mastercard
https://finance.yahoo.com/quote/MA/holders?p=MA
Visa
https://finance.yahoo.com/quote/V/holders?p=V
Discover
https://finance.yahoo.com/quote/DFS/holders?p=DFS
..
They also got Ebay
https://finance.yahoo.com/quote/EBAY/holders?p=EBAY