0) Dockerfile is amazing 1) Let's make something else so we can commit it, and get famous 2) buildpacks.
The core goal of the Paketo Buildpacks project is to improve corporate control and compliance when building OCI images. This is driven from the needs of large enterpise with many disconnected teams all pushing images.
How can an enterpise ensure all those images are built using standardised base images? How can they rebase the base image of running containers without needing every team to rebuild their image using the latest security fix? Buildpacks solves these problems. "Look, no Dockerfile" is a bit of a distraction from the projects main purpose.