The "Dark Age" in the Indian Empire was a period known for a series of rebellions that occurred against the ruling Kushanas. This happened due to the lack of legitimacy by them during the beginning of the 4th century. This created many small kingdoms within the provinces of India and fractured the empire. A lot of unregulated commerce happened during these provinces and there was little to no control by the Empire.
However, when Samudragupta rose to power, he started a campaign to unify the territories of India. Gradually annexing province by province as he went through them. This brought order as the trade was now regulated by one only entity which was the Empire.
There was a contested election but Adam's won
Technically, yes, it is true that the development of the middle class signaled a decline in the importance of nobility, since people were able to have more economic freedom.
