... Containers were a security boundary?
No no no.
It means I can run something that needs a different dependency version than another service .... Without and clash.
That's the isolation. That's what the isolation means.
Maybe it's the wrong word to use, hence the confusion.
Just cause it's "awkward to get into a container" so it looks like a sealed box, doesn't mean it's actually a secure sealed box.
That box has different dependencies than this other box.
Oh, and these boxes? Yeh, they just run on any host set up to run boxes.
But there is no security