Aryeh3, I doubt that there are millions of Jews today who are Shomer Shabbos. Only about 15% of Jews are frum today.
In Europe, there was constant poverty, decrees, regulations about what professions a Jew was allowed to practice, and of course pogroms and anti-semitism that made life almost unbearable. Do not oversimplify and make it seem that these Jews went off the derech simply because it was more fun to do so. They had nisyonos that hopefully we will never know.