Exactly! Now that one use case is established (with another being actively cultivated) it's time to build out the things necessary for world domination! 
With the recent evolution of SPM, platform-agnostic Swift is becoming much more viable (for me) to develop. The more that part of the eco-system develops, the more compelling Swift is for developers/companies to use for new libraries. Jump ahead to having memory-mangement and C++ integration and Swift may soon be in a league of it's own!
Side-note:
Where do Swift Playgrounds fit into the ecosystem? Is that a Swift thing or an Apple thing? It's a really nice way to play with the language and test things out, but it feels like it's kind of gotten lost in the shuffle the last couple years.
With good SPM integration (and some performance/UX improvements) it would be a perfect way to test out new libraries!