The real overhead now is in interfacing: your CLI screen still needs to output (probably) VGA graphics, you'll need USB host support, wired and wireless networking, more sophisticated file systems...

From my point of view that is still kind of catching up with big iron UNIX and mainframes, revienting many of their ideas that were already a thing in the late 90's.

For example, my first experience with containers was with HP-UX Vault, likewise for most fancy filesystems that GNU/Linux might be getting.