Containerization was basically a way to get rid of the problem of "it works on my machine", mainly the OS version and installed libraries. Plenty of instances

Containerization was basically a way to get rid of the problem of "it works on my machine", mainly the OS version and installed libraries. Plenty of instances where program X will work on system A, but not system B, but program Y works on system B but not A. Or X is supported on Redhat/Ubuntu/etc. but you can't or don't want to build from source. Even if that is not a problem, you avoid having to install the kitchen sink on your host and make sure everything is configured properly. Just get it working on a container, build and image and spin it up when you need it. Leaves the host machine fairly clean. You can run a bunch of services as containers within a single host. No cloud or k8s needed. docker-compose is sufficient for testing or smallish projects. Also, there is a security benefit because if the container is compromised, problem is limited that container not the entire host.