The main advantage of containerized applications is their portability and scalability. Containers encapsulate an application along with its dependencies, enabling it to run consistently across various computing environments. This eliminates the "it works on my machine" problem, facilitating smoother development and deployment processes. Containerization also allows for resource optimization, as multiple containers can run on a single machine, enhancing resource utilization. Furthermore, container orchestration tools, like Kubernetes, enable dynamic scaling based on demand, making it easier to manage applications in cloud-native environments.