TL;DR summary: The actual glass the lab flasks were made of mattered.
Miller's lab flasks were made of borosilicate glass and this caused more organic compounds to form than a more truly inert Teflon flask. But Earth's crust is over 90% silicates which could have similarly contributed to the formation of organic compounds in ancient pre-life earth.
I thought the more important fact was that the original experiment produced a bigger variety of aminos than previously thought, discovered by re-examining the original material with modern tech.
Miller's lab flasks were made of borosilicate glass and this caused more organic compounds to form than a more truly inert Teflon flask. But Earth's crust is over 90% silicates which could have similarly contributed to the formation of organic compounds in ancient pre-life earth.