While I think it's just a honest overlook by the author (C++17 is just really new), I still think it's funny that a huge portion of the entire article and by extension the argument against variants is rendered moot by RTFM.
I think the author's goal was quite obviously to have strong sum types with compile-time safety and branch resolution. In other words, to make it impossible to use the value stored in the variant in a manner inconsistent with its type because doing otherwise is a compile-time error.
The above parts of the standard library don't help in achieving this goal.
