[icedchai]

Docker is native Linux. Your app uses the same kernel as the host. Is "chroot" middleware? No. Neither is docker.

[consteval]

It does require a running daemon. Other solutions, like podman, do not. There is an overhead associated with docker.

[icedchai]

Yes, but containers do not incur overhead because of the daemon. It is there for management purposes. In other words, system calls / network access / etc are not going "through" the daemon.