What are the reasons for the later development of the Eastern Slavs in comparison with the Franks

What are the reasons for the later development of the Eastern Slavs in comparison with the Franks, although at the beginning of the 6th century they were at approximately the same level of development?

The Eastern Slavs, who were in the vicinity of the Franks, formed a state much later than their western neighbors. Development was slow due to the lack of access to the sea, where world trade was conducted. The Slavs could trade only with merchants traveling along the route “From the Varangians to the Greeks”. Also, development was hampered by the frequent raids of eastern nomadic tribes and the slow pace of development of the economy and crafts. The Slavs did not strive for unification, since they did not have a unanimous decision on the prince and the capital.