If it's like most things, it's a matter of prioritization. Trying to maximize positive impact with a limited set of resources forces you to prioritize.
Sure it would be great to get rid of unleaded aviation gas, but ensuring we don't get a repeat of the 737-MAX issue might take priority.
Sure it would be great to get rid of unleaded aviation gas, but ensuring we don't get a repeat of the 737-MAX issue might take priority.