(imagination can also be used to reduce programming complexity and asset creation because you basically make the player a co-creator)
So can procedural generation, although programming an artist might be more painful than just hiring one
I completely agree about the power imagination has in games. This kind of reminds me of the art revolution in the twentieth century - the camera made representational art pretty pointless, so artists turned to more abstract works. In gaming, today's technology allows one to create realistic worlds and simulations (light, physics, particles, etc.), so to move forward as a medium game mechanics and graphics need to become more inspirational than representational.