Brian Acton is the only billionaire I can think of that hasn’t been a net negative.

Co-founded WhatsApp, which became popular with few employees. Sold the service at a reasonable rate.
Sold the business for a stupid large sum of money, and generously compensated employees as part of the buyout.
Left the buying company, Facebook, rather than do actions he considered unethical, at great personal expense ($800M).

Proceeded to cofound signal, which is an open, and privacy focused messaging system which he has basically bankrolled while it finds financial stability.

He also has been steadily giving away most of his money to charitable causes.

Billionaires are bad because they get that way by exploiting some combination of workers, customers or society.
In the extremely unlikely circumstance where a handful of people make something fairly priced that nearly everybody wants, and then uses the wealth for good, there’s nothing intrinsically wrong with being that person.
Selling messaging to a few billion people for $1 a lifetime is a way to do that.