All much slower than native containers. My Docker daemon on Linux doesn't take 15 plus seconds to start and dynamically utilizes my CPUs and memory from the host.

Same with a hypervisor? A hypervisor could start as fast as a container, the only issue is having two kernels and the overhead it entails.

Not it can't, unless they build Docker containers into the Window and Mac kernels with the Linux subsystem.

Yes, but we don't (yet) have cross platform containers

I think only plain Qemu can run unprivileged

https://github.com/linuxkit/linuxkit/blob/master/docs/platfo... looks promising