That is not “a lot” of changes.
Many technologies were originally conceived/created years ago, and then hardware caught up.
Shaders, for example, were originally created for renderman which is … 25 years old?
Ideas used in 3d rendering can be traced back to a fairly old research paper. While initial release of, say, OpenGL, is marked as 1992, IIRC there were articles describing polygonal rendering/stencil buffers/etc BEFORE that.
It was all about using tried approach for quarter of a century and continuously adding more transistors to the graphic chip to make it able to draw more polygons and have larger textures.
I simply think this is not good enough.