Well other than the obvious fact that it is dangerous because its outlying kingdoms were vulnerable to invasion. Another thing they had to worry about was certain trading groups would become too dependent on their necessary goods.
The Vedic Age in India (c. 1500 BC-c. 500 BC), also known as the Vedic Period, was the time when the Vedas (the oldest sacred texts in India) were written. During the earliest part of this period and even the period which preceded it, economy was mainly characterized as being self-sufficient, so trade was not so popular. This meant that there were some drawbacks of voluntary trade, for example:
little scope for product exchange
households produced just the necessary supplies for the family
the surplus was stored for future use
the different neighboring areas were not connected by trade, as they were self-sufficient
each farm produced their own grains, clothing and other commodities
roads were poorly made, so trade was difficult - they traveled down the rivers instead of roads
