I do not believe the Census Bureau has stopped sending census-takers. Rather, they have largely automated some of the decennial census data where they are confident of receiving accurate counts and, instead, focus their census-taking person counters in areas where they may be uncertain of getting an accurate count.Not too long ago, the Census Bureau asked Congress if the decennial census could be based on sampling the population. Congress, knowing that the counts serve as the basis for representation in the US House of Representatives, said no. In short, not only must the Census be based on reported observations (takers and mailed-in counts), this method also preserves some of the flaws in the system that can allow states to challenge the Census counts (and number of representatives derived from them) in court.