What do you mean by "Just using Guix requires a pretty substantial amount of administrative work."

Like, as a user downloading packages, or a person packaging an application?

As a user downloading a package, it's been super easy for me and it's been years of running Guix with little to no issue (yet the benefits of rolling release, rollbacks, installing multiple versions of a given software etc.).

As for using it to package an application, I found the challenges mainly in the documentation. This was years ago and a lot of work has gone into improving the docs.

I'm curious what your experience has been.

FWIW, not the OP but doing a guix pull after getting it from APT took several hours to crash out every time I wanted to just try using guix for something, and the ISO to install it from upstream was multiple gigabytes which seemed wild. I put a couple days into it and never actually got to try it.

It's hard to have an opinion of a platform you haven't used but based on how bloated just starting it seemed to be I was unimpressed.