Docker build arguments provide flexibility and customization in the image-building process by allowing users to pass variables during the build without altering the dockerfile itself. This approach is particularly useful for modifying aspects like runtime versions or environments while maintaining the consistency and reproducibility that Docker images are known for. The process involves defining arguments in the dockerfile and then using the --build-arg flag to pass values during the build command. Examples given include a simple demonstration with an Alpine Linux image and a more complex application with a .NET project, where build arguments are used to set the environment and version settings. The distinction between build arguments and environment variables is highlighted, emphasizing that the former is for the build process while the latter is for running containers. The article suggests that using Docker build args can streamline the development workflow, and mentions DevZero as a tool to further optimize the image-building process by offering cloud-based development environments.