There's no archaeological record of modern man using these rocks to make fire easier.
Maybe Neanderthals were not dumb or inferior cognitively to man.
I suspect their small numbers were destroyed, mostly, by diseases they had no immunity to.
There’s never been any evidence of Neandertal inferiority, that began as an invention of R. Virchow, and along with complete replacement by the master race has been enshrined by the unreconstructed darwin worshippers of the UK and beyond.