The reason AWK is not widespread is that it's only great for one case: working on a stream of lines. It's a pretty narrow niche.

Sure you can code anything with it, but there is always another language that will be better at this other thing, and still decent at what awk does. Awk looks more like a DSL than a generalist language.

So why learn awk to save you a few minutes for the rare cases you do need it? Just learn Python/Ruby/etc, it's a better investment, and it has a better crossplateform story.