Starbucks probably would not be what it is today without William H. Gates Sr., a lawyer and father of the Bill Gates who co-founded Microsoft. The attorney was instrumental in helping former CEO Howard Schultz buy the coffee company in 1987.
https://www.cnbc.com/2017/10/04/bill-gates-sr-helped-howard-schultz-buy-starbucks.html
This makes me think Bill Gates father was already rich and Bill Gates was rich because his father was rich and that he was not a self made millionaire or later billionaire