Sudoku is an exercise in trial and error and like all such exercises is vulnerable to a computing solution. Simply write a program that allows for all the variables and constraints and let it run. Simple, so simple in fact that people can do it in their heads.
A crossword puzzle is more complicated, so complicated in fact that people can do it their heads. The difference is that any computing solution to a crossword is limited by the fact that the grid has to be filled with words that fit AND that answer the clues. Inherent in this is that filling the grid is not enough.
Search is Sudoku. View, click, action – it’s a math problem. Display media online, and in print and on television is a different matter, a crossword puzzle if you like. As soon as the goal is anything other than inducing a purchase in 30 days or less it may still be possible to fill the grid but much harder to interpret all the clues that identify which components contributed to the desired action and when.
Is it possible that this has been the gating factor to Google NOT dominating the media landscape as they have dominated search? Could be.