Doesn't matter if it's widely known, it honestly is much nicer to work with than Javascript and is being used as it is intended, instead of being a half-baked language designed in a hurry, to work in a browser, that got repurposed as a general purpose scripting language later.
Game dev, possibly (even that seems highly debatable). But the article was making the case that Lua should be more widely used outside of that niche.