Simplification i.e. the process of reducing complexity, exacts a non-linear cost because the process of identifying complexity-reducting factors is complex. If it were not so then the substrate would not be complex. Simple substrates require linear effort in order to reduce them.
My suspicion is that this non-linearity is typically exponential: an exponential effort is required to achieve correponding gains in simplicity. As Robert Heinlein said, "there's no such thing as a free lunch".
The amount of time, therefore, that must accrue before such gains are observed is enormous though the previous exponential gains somewhat accelerate the process.