> However, getting to that stage, unless you're packaging a collection of plain files with very simple dependencies, is the hard part.
What do you mean plain files with simple dependencies? A deb file is just a zip that stores metadata and your artifacts exactly where you want then to be in the directory structure you see fit. You specify the packages you depend on in the meditada, zip them up, and that's it.
If you need something fancy you can add shell scripts that are triggered in parts of the installation lifecycle, but those are far from being mandatory.
Hell, if you prefer to follow the lazy way out you can even get build systems to generate your deb files for you. Cmake handles this out-of-the-box.
> Ignoring the weird scaffolding you need just to package a static "hello world" binary
What? That "weird scaffolding" you're referring to is literally the directory you zip with the artifacts in their destination and the metadata! Is it too weird for you to deploy libraries in /use/local/lib before you package them? What are you talking about? You build your static "hello world" binary, you place them in the destination folder, you fill in the metadata to specify dependencies and stuff like your name and email address, and you proceed to zip up the package. Done.
> (...) found like 5 different ways documented on the debian wiki
No you really didn't. At most you found references to 5 different tools that help you do the same exact thing.
Here's a link to a process you tried to described as undecryptable:
https://ubuntuforums.org/showthread.php?t=910717