There has already been an enormous amount of effort expended showcasing and promoting Julia on the forums you mention and others. The material is mostly of very high quality. You can also find this easily. Asking for more or better isn’t a good approach IMO.
People often choose other languages over Julia, eg Rust, not for lack of advertising or even libraries, but for fundamental reasons, such as interoperability and ease of deployment. These are hard to solve and resource intensive and have had to compete with all the other really important stuff; just to grab a couple of things at random: BinaryBuilder and Pkg. Still these problems around interoperability (but not only interop) are being worked on.
So it’s much more than just libraries. And some Python libraries have armies as big as the Julia dev community working on them. It doesn’t make sense to set beating them as a goal. Furthermore Python is written in C, has always relied principally on C extensions. Rust is nearly a drop in replacement.
There are so many other reasons. Rust and Julia are very different. Sometimes people just enjoy writing in Rust more than Julia and vice versa. Maybe a matter of personality.
The questions of exposure and promotion that you mention are important. But, these questions as well have also been discussed in Julia forums in great detail (or at least great quantity) for many years.