Your first paragraph appears to be a sarcastic paraphrase of the article; please correct me if I'm misunderstanding that. What's the somewhat custom use-case, and what's the option that jacks up the size? I don't see anything in the article that would obviously fit either description.
The option is LTO
A very quick paraphrase, sure. Don't really think it is sarcastic, but whatever.
The custom-use-case is the article's very raison-d'etre: "... I wanted to distribute a static library and the size was causing me problems. Specifically, I had a Rust library that I wanted to make available to Go developers."
The option is LTO.
The situation here is a bit like building a binary with debug info, and then saying, "But I don't need debug info and it is causing me size-problems, so I'll strip it." But the better option is to not build with debug info in the first place.