I admit I like tactical goodies as much as anyone, but there are times when old stuff comes in handy - when for some unaccountable reason, you don't have your trusty blade handy. Stone tools (flint, chert, or obsidian) can be razor sharp, sharper even than the finest steel edge, but they are very fragile and don't last very long. Resharpening is possible and fairly easy, but that is another story...

If you don't happen to be a master flint knapper and you need a sharp edge, just grab a handy hunk if chert and bust it up, selecting a handy sharp edged piece, and slice away. Whole elephants have been butchered in this way.

Really good flint sources were highly valued and widely traded. It is easy to imagine our ancestors sitting around a campfire, hotly debating the merits of Alibates Flint vs. Yellowstone Obsidian, much as we do D2 vs 154CM, etc.