Non aviation people don’t have a clue what is involved in an STC. Just go down to the STC store and pick one up, I mean, y’all are rich after all…
What does an available STC have to do with the fleet of Experimentals that are hodge-podges of components scavenged from fly-marts and tossed into an aircraft? All those pieces are working fine with 100LL.
Until a substitute has been in the field and accepted as reliable, 100LL will need to remain available. That may require a decade of public use. That may require lower prices to incentivize the use of alternatives over 100LL.