It’s the same approach as gVisor. Fairly decent isolation if your application can work on it, but your SOL if a scenario comes up that doesn’t work. VMs give you pretty much 100% Linux compatibility at the expense of density, optimal resource allocation and startup time. gVisor gives you excellent startup time, resource allocation and density at the expense of some app compat and performance at the extremes

Edit: at least with gvisor you get close to a decade of work on compat. gVisor can support some rootless containers scenarios and systemd these days.