You would have to define "Western history". Greece probably did fairly well, and did so without "Christianity". Although they killed Plato just as the Roman Church/State killed and intimidated any that shook the boat. Rome fell apart fairly quickly after Constantine established the Roman "Christian" church, although other off shoots soon took up the mantle, and helped intimidate and kill those who shook the boat.
Now if you are referring the the American experience, I think that was the result of principaled men such as Jefferson and Franklin, who were free thinkers, and although were raised under the Protestant work ethic, felt free to disagree with conventional thinking. Jefferson went so far as to edit the bible, leaving out as much of the leaven as he could.
As for if it could have been worse, that is a possibility, but I would not be able to ask the victims of the pogroms of Spain, or the extermination camps of "Christian" Germany, for they are dead.
As for will things change, yes they will, and the nations (Gentiles) will confess that they have inherited nothing but falsehood. (Jer 16:19) But this will come in the "day of distress". And what was one of the falsehoods inherited by the Gentiles? That would be keeping the traditions of men in the form of the feast of Astarte, Easter, which has nothing to do with Passover.