The prayer Lecha Dodi was composed in the 16th century which is relatively recent as the general Nusach of prayer was founded between 516 BCE – 70 CE by the Anshei K'neset Hagdolah, and its rare that everyone, ~2000 years later, adds a set prayer (not counting Piyutim - poems - on holidays) to the service.
What was so appealing about it? Why did almost every community add Lecha Dodi to Kabalat Shabbos?