Scoop installs directly from the first-party source, so you only need to write a package once per app, instead of once per version of each app. Are there any distros that work like that?
It sounds a bit like a good reason to use PPAs in some ways. But the rest of your writeup above is also the exact reason you want multiple ways to go about this thing, rather than one way. I think I use at least six different methods of getting the software, each with various strengths depending on the situation.
For example I see that Scoop runs best with "portable" apps and links directly to those third-party binary web resources. But what does the Scoop ecosystem do about third-party platforms that require special compile-time flags? Typically that's where a third-party repo maintainer would come in.