It won't stop the use of leaded fuel until the FAA bans it, which should have happened decades ago. Your airplane can't fly without unleaded fuel? Cool! You can stare at it in the hangar!
Jet engines are completely different from the piston engines you'll find in general aviation (sans choppers, which mostly run on jet engines).
Piston engines need leaded fuel for lubrication as well as knock resistance, and deviating from the original certification of the engine/plane requires a type-specific certification - every model of plane you want to fly that was certified with 100LL AvGas needs to be separately tested if it can fly safely with lead-free AvGas [1].
[1] https://www.flightglobal.com/engines/faa-approves-100-octane...
I do think some European engines have looked at diesel though
There is no other reasonable choice. Lead fuel has to go away simply because of the amount of lead that deposits all around GA airports.
Pretty much everyone in general aviation who is using leaded fuel wants to get away from it. It clogs corroborators and exhausts, requires special mitigation for spills and handling, and is generally not great.
The FAA approved and is now working to promote GAMI G100UL to replace leaded fuel in aviation, the big roadblock is passed as it is approved for all engines for which 100LL was approved for. So the phase out will go as fast as FBOs switch and GAMI can manufacture or license.