Cross-platform applications that rely on binary libraries have always been the beginning of my Python dependency misery. It usually works fine, but when it doesn't, it's miserable.

Same for me. Does rye help? Or what's your silver bullet?

PyInstaller + bundling the dlls and binaries works well for me

One annoying problem that I encountered with that approach was different binaries having different version conflicts on different platforms. Not unsolvable, but definitely unsolvable without a whole lot of irritation, and a huge PITA to maintain. It definitely makes it possible though, which is a whole lot better than nothing.

I haven't encountered any silver ammunition for that particular gun. I haven't worked on a big python project in a while, so I'm not sure if rye would do the trick.

I get that, but isn’t that a problem with dependency management itself and not the tools?

Try making a portable package that pulls pytorch with CUDA (reliably) with that set up. I don't even think it's possible as you can't add another package index when using python build.