In southwestern Germany, genealogy usually stops at the Thirty Years' War [0]. Where I come from, the population decline during the war was more than 66% [1]. Most church records were either destroyed in battle, or used as a heat source during the winter. Very often, people just stopped keeping birth records.

[0] https://en.wikipedia.org/wiki/Thirty_Years%27_War

[1] https://upload.wikimedia.org/wikipedia/commons/5/57/Bev%C3%B...