The same package manager, but different enough packages, PPAs, etc, and a different release process.

Many different technical decisuons.

A very different project governance.

I'm not implying that these things are bad! But different enough they undeniably are.

The fact that I can install .deb packages on my box using a port of apt does not make it Debian. (Saying this as a dedicated Debian user since 1998 and until the switch to systemd.)

I realize the above comment took more effort than parroting someone else's 9-word statement. Thanks for putting the effort to expounding on the differences between milk and grass.