[snotrockets]

All of academic output is an incremental improvement (it may differ for the social sciences. I don't have experience with that.) Newton famously acknowledged it in his letter to Hooke.

We also have the misfortune of struggling with the deep unknowns, as all of the trivial theorems have already been proven before (consider Feynman's definition of trivial in 'Surely You're Joking, Mr. Feynman!', New York: W. W. Norton, pp. 69-72, 1997.)

But some improvements are greater than others. The question is where you draw the line. And I hold that most researchers' line encompass more then yours. Consider, for example, Jiří Matoušek's opinion of Computational Geometry in 2010 (to save you the reading, he called it no less than an annus mirabilis. You can read his reasoning here: http://kam.mff.cuni.cz/~matousek/mor.pdf)