I don’t think containers, as normally used, provide that much security because so much of what you want to secure is at the boundaries between containers (the network) rather than inside the container itself.

There’s not much point in preventing hyper visor escape style exploits if the agent can just SSH or psql log in to an adjacent container. Likewise there are near infinite ways to do weird things with the network to make stuff happen in another less controlled environment (eg sign up for AWS free account, make VM, do everything on that VM where controls don’t apply).

There are tools to do this, but I’ve never seen anyone package them up in a way that was pleasant to interact with. It’s got the SELinux problem of being useful, but annoying enough that everyone just disables it the second it gets in the way. It’s surprisingly hard to manage what should be able to connect to what as you start scaling out the number of things on the network. Whoops, you forgot that random software embeds its own DNS over HTTPS resolver so the normal DNS profile won’t work and everything crashed kind of issues.