The point that makes this different from an OS is that there's no shared service, no syscalls to do that stuff -- just subroutine calls -- and no timesharing (except at the hypervisor level). It's just a single runtime running on hypervisor direct against the virtualized hardware.
Because, yeah, all this work has happened in hardware in the last 30 years to make that possible, but we still treat the operating system as the best unit of resource sharing. When in fact it's kind of a jack of all trades master of none. If you're booting a whole linux kernel -- with its giant framework built to co-tenant a pile of applications and users -- just to run one process, there's definitely something to look at there. Even if the unikernel space itself is relatively immature.
You don't need to emphasize the "vibe coded every time you need them" thing. That's not what anybody was being talked about in the article. The "vibe coding" piece is pointing out that the missing pieces in the ecosystem can be more rapidly filled in now because of agentic tooling.