I can imagine that having a swift backend for your swift mobile app would be a lot nicer to work with than converting back and forth from a bunch of stringly-typed JSON.
Yes, this is it precisely. Swift already has decent momentum for serverside usage with Vapor, Perfect, and Kitura among others. By adding LSP support, Apple is adding to that momentum and pushing it closer to critical mass.
I'd love to use Swift on the backend, but I don't want to use XCode.
I only develop part-time, as my main job is financial in nature, but god, it is really hard to find good learning material for serverside without depending on XCode. In particular, learning the server frameworks is almost not worth it. By using one language, I can keep my productivity acceptable.
If anyone has any references, I'd be super thankful!