Alcohol & lead free fuel has been in use by many operators over many decades now. When I first started flying, I could find mogas at many airports at a reasonable price, either cheaper than 100LL or at the same price. I STC’d my a/c when I bought it @ 250 SFRM, and continue to run it to this day. I ran that engine primarily on mogas, to double TBO, twice. Aside from the engine basics: lead is bad for engines, lead is also bad for living things. I fly on the average 300 hrs per year, my home base does not carry unleaded fuel so I, and many others tanker it in. They used to carry it, but complained that they didn’t sell enough, so they dropped the tank when the new FBO came on board. The field had 100LL, Mogas, and Jet A when the new FBO took over. The first thing done was the price of fuel increased 25% across the board. The second thing done was mogas was dropped and the price of 100LL increased another 15% to be the third highest in the state where it remains to this day. My missions are 700 nm so I had justification for adding ER tanks and now tanker mogas. My second base does not have mogas either, but its 100LL is nearly half the price of my other base. Mogas is available 20 nm away at half of that price. The FBO owner is now complaining that he is not making enough on 100LL because the JetA volume is so much higher that it’s not worth it to pump it to him. He prefers to refuel the regional jets and the turbine equipment and regards the 30-100 gallon tops of the GA tenants as a bother. Obviously 2000+ gallons in a CRJ or 8000 in a B737 is a preferred load. The airport board did an analysis. JetA is competitively priced because the airlines will tanker fuel. 100LL is priced because the FBO can.
I disagree with your premise. The market is already split was always split. Before it was discontinued, 80 sold for the same price or slightly lower than 100LL or 100. 80 was available at 90% of the airports I flew into, pretty much all except Class B airports, and even then some had it. It is split between turbine and piston.
Those who can, have moved to mogas from the automotive pumps, test it for alcohol and put it in their airplanes in jugs or from mounted transfer tanks. I have pumped well over 8000 gallons into my plane alone this way. Not because 100LL is too expensive (it is far too expensive), but because it is better for my engine and the environment. Extending my TBO times and spark plug life is a huge bonus.