Look at the syscalls chart. It's hard to tell exactly what the numbers are on the log log scale on the syscalls chart, and it's probably not the graph I want anyway, but it looks like their runsc-kvm platform clocks in at 1k ns/syscall while their ptrace platform looks close to 100k ns/syscall. The fact that it's log log is telling alone.

It's just log, not log log. The chart generates from .csv hosted on the site [1] and the benchmark tools are all open.

The ptrace numbers are 20x and the KVM platform is actually lower than the Docker default case (though that doesn't mean everything is faster, as system call time is only one factor). As I note above, I think you're confused about what the KVM platform is -- it's not a VM.

[1] https://gvisor.dev/performance/syscall.csv

Missed that one. The gVisor calls are closer to 40k but the difference is indeed big.