Oil and Gas billionaires leverage the fact that society hasn't figured out how to factor in negative environmental externalities. Consumer Staples billionaires leverage their supply chain monopolies and labor monopolies.
The original tech billionaires leveraged their early knowledge of computers/internet. Web 2.0/3.0 billionaires leverage the fact that society hasn't figured out how to appropriately regulate stuff that's similar but slightly different from their old school regulated counterparts (i.e. Uber, Airbnb).
In general, leveraging technology capabilities seems less exploitive than leveraging human/environmental resources/lack of regulation.