When business culture and expectations are not clearly defined — especially during times of high growth — the result is confusion and lack of morale. This is true of many small details, like how to answer and route phone calls, as well as big things, like operational management.
A business, overall, must be structured in a way that can support its potential. In my experience/opinion, failing to establish this early on inhibits growth and causes serious issues with stability in the short and long term.
It’s important that the example is set, led, and communicated by leadership to define the company culture and add structure that will sustain and reinforce every business function in a unified direction.