I think calling it a SAT solver is appropriate here. A lot of package managers were "organically grown" i.e. they were created in response to a problem that arose. Not much thought was given to the underlying problem and in the long term users suffer with e.g. dependencies taking forever to install and strange deadlocks. Recognizing it as a SAT problem from the start means we can easily throw Z3 or similar at it instead of manually adding heuristics everytime a user files a GitHub issue. (See Bundler and other pre-2018/2017 package management tools for example) Also, it's not always a SAT problem. For npm, Java Classloaders it's just tree traversal because conflicting sub dependencies of a dependency can co-exist.

That said, the Go's team (and to a lesser extent Python's too) dropped the ball here. None of the challenges of dependency management was unknown or unsolved. Anyone who has used e.g. Maven should be more than familiar. (A 11 section blog post is indeed nice though, good for onboarding new programmers I suppose) If developer experience was considered a first class priority, this could have been solved from day 0.

(My personal favorite is NPM since conflicting dependencies can co-exist at the expense of greater disk usage, but memory is cheap these days. No one with an electron app on their desktop has any right to complain about the memory usage of plain text source code.)