The fact that containers are such a simple technology always makes me think this:
Why is it still necessary to have whole, full-blown OS filesystems inside of our containers, if their purpose is running a single binary?
Dependencies/dynamic libraries are decent reason, sure. But wouldn't it make more sense to do things "bottom-up"? i.e. starting from an empty filesystem, and then progressively adding the files that are absolutely necessary for the binary to work, instead of the "top-down" approach, which starts from a complete OS filesystem and then starts removing the things that are not needed?
Lots of examples without the entire OS as other comments mention, an example would be Googles distroless[0]