I still find it crazy that piston engine aircraft still run on leaded fuel. The only reason it is still the case is mostly regulatory. We can make compatible unleaded fuel, we could have done it decades ago, but it would have required costly recertification and maybe minor retrofits and the use of additives, and considering the small scale of GA, considered not worth it.

Things seem to go in the right direction, with an unleaded alternative in the process of being certified. But aviation, especially general aviation moves at a glacial pace, usually for good reasons, maturity is important, but not poisoning people is important too.