The really rich people all have jet planes which burn jet fuel (no lead.) It's the upper middle class that have lead burning piston prop planes. Dentists and doctors, not billionaires.
Anyway, unleaded fuel is now approved for those planes so the transition should be pretty quick now.
Yes, it's somewhat funny. Our commenter consp almost suggested that people with private planes _want_ to burn leaded fuel, when unleaded fuel wasn't even legal to burn in them.
Anyway, unleaded fuel is now approved for those planes so the transition should be pretty quick now.