Molly - don't think so. Flint, chert and obsidian all flake to a molecular edge - sharper 'points' than can be accomplished by filing. Not to say your "filed" flints are not sharp. The knapped, but rough/serrated edge of a knapped flint will scrape steel to incandescent heat better than a filed edge simply because of the lower coefficient of friction compared to the longer smooth surface, I think.
I attempted to make some 'emergency' flints from Tungsten Carbide but the best I got was dull red sparks. They were SHARP, felt incredibly sharp, but failed miserably on the frizzen, in comparison to flint or chert.