I would love to see more development in this space. I'm aware of tools like bazel, nix, and jib (I feel like I've seen an equivalent to jib for Go) that can build Docker images "outside" Docker/BuildKit. I believe the .NET SDK can do something similar for .NET applications. And then there's tools like buildpacks, nixpacks, devbox, etc that still use Docker to produce the image, but don't require thinking in Dockerfiles.

I have some ideas I want to explore with Depot, but it really it feels like it should be possible to make cross-compiling and dependency encapsulation easy to use, so "building a container image" is reduced to creating a tarball in the correct OCI format, and you don't have to interact with Dockerfiles as much if you'd prefer not.