Do you think Late Antiquity was a period decline or foundation?

Very good arguments can be made for viewing Late Antiquity (ca. 200–800) as a period of decline or one of foundation. Many scholars take the stance that both characterizations are simultaneously valid, as the evaluation depends on the society and geographical area on which one is focusing. For many years, the period that began with the waning years of imperial Roman power was invariably considered one of decline. This idea was promoted by Edward Gibbons’ 1776 work, The Decline and Fall of the Roman Empire, which established a position that remained largely unchallenged until the twentieth century. However, positing Rome as uniquely central in cultural development and the pre-Middle Ages as essentially devoid of civilization has been heavily criticized as an ethnocentric perspective. Numerous other societies were developing in Eastern Europe, the Middle East, Central Asia, and Northern Africa.
Significantly, the spread of Christianity in the Eastern (or Byzantine) Empire and the birth of Islam during Muhammad’s lifetime occurred far from Italy. Scholars have argued that during these five to six centuries, the network of communication and, to some extent, shared values united a geographic area and laid the foundation for further cultural development. Despite religious differences, for example, a changeover to the primacy of monotheism characterizes the era.
https://www.oxfordhandbooks.com/view/10.1093/oxfordhb/9780195336931.001.0001/oxfordhb-9780195336931-e-0