Yeah, GNU Guix is what comes to mind here. It can be run either as an OS or as a package manager on an existing GNU/Linux system.
I run Guix on top of Mobian on my PinePhone and the packages themselves “work” about as well as a native Mobian package, which is to say it is hit or miss. The real issue with Guix is that it’s fundamentally a source based package manager, although it can get binaries from a build server. As can be expected, most of the work is put into x86-64 and although aarch64 is technically a supported target, some packages don’t have binaries for that platform and some won’t even build (I had a “fun” time trying to build a Haskell package for my phone).