This is kind of a difficult question to word, so I apologize for any vagueness about this topic, but I will try my best.
From my understanding, Ancient Europe seemed to have a really diverse and broad degree of cultural diversity and technology, from the Celts to Latin Rome to Germanic tribes to Hellenic Greece to the Iberian cultures to the Norse. These cultures all seem very unique and distinct from each other, but as I look more into European history, somewhere along the way I sort of notice that European culture as a whole seems to become increasingly similar, especially during the early modern period, where European culture as a whole seems very uniform (For example, comparing ancient Norway to ancient Spain, they would seem totally alien to each other, but in the early modern periods, they do have their differences but they might seem more alike then different).
Obviously, each nation and people retain a significant amount of independent national and cultural significance, but overall, Europe at some point seems to have gotten rid of the diversity in unique ways of life in favor of homogeneous ideas like urban living, agriculture, firearms-based warfare, etc. Even the clothing for most of Europe seems to become very similar in the early modern period, although there were difference between fashions in countries, from my perspective it seems very similar overall.
Is there any specifiable point where Europe went from these diverse cultures and ways of life into the more homogeneous 'civilized' life we know of now?
EDIT: Spelling. Also to clarify, I mean 'barbarian' in the classic Roman sense, as in a culturally different from Rome, or in this case really just from any cultural perspective, which would be any number of varied cultures from around Europe
Source: reddit post