"Jailing" isn't necessarily just about security, but isolation in general. Unveil would be a stronger tool if the concern is strictly security, but also there's

"Jailing" isn't necessarily just about security, but isolation in general. Unveil would be a stronger tool if the concern is strictly security, but also there's no reason they couldn't both be used. Chroot is itself sometimes used to provide container-style functionality, so I think it's wrong to say containers "surplanted" it.