Oh wow that sounds exactly like the kind of problems package mamagers solve. Your complaint basically boils down to - nobody prepared a one click package of latest version for free for me.
My complaint comes down to the following: why must there be a middle man between the developer and user, why must there be a separate middleman for every repo, why must said repo prevent me from installing older versions, why must the package manager prevent me from installing to alternative paths... basically, why does the community insist that this simple task that was the de-facto way to install software for DOS, MacOS (classic), NeXT, RiscOS, and MacOS (recent) insist on being complicated and restrictive in Linux?
And if package managers really solved the problem, why do so many projects deploy with Docker? Why do FlatPak and Snap exist, let alone my preferred AppImage?
> why must there be a middle man between the developer and user, why must there be a separate middleman for every repo,
Guix allows you to easily write own package definitions which are treated as part of the whole system. If you submit them and they are accepted, they simply become part of Guix.
> why must said repo prevent me from installing older versions,
Precisely this is a case that Guix solves extremely well: One can start environments with specific versions of packages, like in Pyhon's virtualenv.
And by the way, the complexity is caused by the issue that many many components need to fit together. That does not happen by chance, it is a massive amount of work to make it fit in a manageable way, and check that it works. That's what distributions do.
And yet many operating systems throughout history have not needed to do that. The complexity is not inherent to the problem space, it is a creation of the community.
And if package managers really solved the problem, why do so many projects deploy with Docker? Why do FlatPak and Snap exist, let alone my preferred AppImage?