At least on Windows, Hyper-V isolated containers are also a supported feature, which should also ensure kernel isolation.
I assume Kata containers or any other virtualization backed solution would give you similar guarantees.
They point of containers is that they do share the same kernel, and that each container is just a different namespace.
If each entity has a different kernel, they are VMs. VMs can be also pretty thin and have shared immutable store for their base image, but they are not containers anymore. Similarly, Xen DOM-Us are also VMs.