Good thing you are not in the government.
'Hobbyists' have been waiting for lead free avgas for decades. You should just crush their planes while you are at it.
While the super rich do whatever they want? By the way, if you are super-rich, you are probably burning Jet-A anyway, not AVGAS.
The real fix is to just issue the damn regulation and provide some incentives. Engines have to be overhauled and replaced periodically anyways. Make it easier to recertify aircraft, provide a path for aircraft that no longer have the original manufacturer around. Give incentives for small airports to stock on whatever the proposed avgas replacement is until the demand catches up.
> flight plans are registered
No they aren't. No requirement for flight plans in VFR.
If you are proposing such harsh legislation, you should at least try to learn something about the subject matter.