Organizations heavily depend on software. Millions, billions of lines of code are produced every year.
This only accelerates in the future. (This may even be a self-accelerating process. I was looking to find an estimated for the numbers of lines of code produced every year, but could not find firm figures. Nevertheless who would doubt the number software based solutions is growing.)
Architecture provide a sense of how all the software pieces fit together.
For organisations this means (enterprise, business, IT) architecture define and assure the organization’s ability the serve customer needs.
Architecture is the organizing principle.
You can survive for sometime without an explicit architecture, but at some point you will hit a wall. Inefficiencies in business processes and the supporting software systems will bring an organization to a halt. Problems with functional alignment, business process and application integration, application support, scalability, changeability and what have you (yes I am being lazy now) will need to be addressed to get back on track.
It is better to get things organized.