Another burning question that probably no one will answer

Given that most people aren't supermen/women, if Halakha prohibited something, what was the likelihood that the Halakha was violated anyway? It is hard to believe that the shtetl dwellers of the past 500 years were all holy people. Thus, was their violation of halacha due to ignorance or the understanding that in this case halakha would need to be violated? How was abstinence / contraception used and practiced in Europe, North Africa, Persia, the Middle East, etc. among Jews of the last thousand years? There must be an answer that does not rely solely on the differing opinions of Rabbis down the ages.