Debugging GTM is a hugely important, and powerful, aspect of the platform. Previously, understanding the data sent with your tags, tracking & scripts required a huge amount of either dev time or understanding of how your entire platform works. Now it can be easily visualized and tested via the GTM debugging tool.
By using the debugger you can truly understand what is happening on the backend of your website when customers or leads interact with your product, services & platform.
With those understanding you can inevitable build a better customer experience. And, inevitably, a better customer experience will lead toward greater revenues, lead acquisition, or conversion rates.