it was replaced by an idioicly stupid lead based chemical and the burning of gasoline with this stabilizer proceeded to literally poison the entire planet with lead.
Tetraethyl lead "Ethyl" was used as an octane booster, not as a stabilizer. It prevented engine 'knock' and enabled higher compression ratios in World War II aircraft engines (both Allied and German) and later in muscle cars. It also helped protect the valves.
I think the Germans typically used lower octane gasoline, especially the synthetic gasoline made from coal. I've read that in post war tests, the US found that it could get a top speed that was 20-30 mph higher, out of German fighters, just by fueling them with our high octane aviation gasoline.