Why? Containers are not insecure, some implementation of them have some vulnerabilities. That doesn’t mean that namespaces are insecure, it doesn’t mean that cgroups are insecure, and there is more than one container implementation (such as podman and cri-o).

That sounds like a reductionist argument, unless you have some more concrete issues than just “they are so insecure”. And having VC money is not a problem per se.

i'm uneasy about the security aspects of running under a common kernel too, but what else would you use for deployment? in my case I've been using it as "light VMs" for cross platform development - e.g. toolchains, or handing over a container to a customer which builds their embedded Linux system instead of a full VM. It opens a lot of possibilities.

"propped up only by vc marketing dollars"

This is just not true. They're propped up by Google's marketing dollars.