The primary valuable feature of NGINX for me is its ability to provide a reverse proxy. I have found that this feature supports our local server, and I am able to connect through our DNS system, making it accessible publicly. Additionally, the integration with SSL certificates and the configuration capabilities make it a valuable solution for my use case. Without NGINX, users would not be able to access our application, which means there is positive ROI from using NGINX as it is crucial for the functioning of my organization.