It does though. As least for me. Better support on Windows and Linux would increase the number swift developers which would the in turn result in more and better open source libraries.
For Apple this could mean that their own open source libraries could get better, they have more tools/libraries to choose from, or simply that they have a greater pool of talent for hiring.
Looking at Go (and Rust) I think this is somewhat shown. There are a lot of different factors, but I think the development tools of Go is the #1 reason why it is basically the only "new" language in a long time that gained a large enough popularity to become mainstream - as in you actually find jobs developing in Go. Which is in some ways sad. It seems like Swift could be the very good fit for backend/serverless development.
I guess the real question is how much effort would it take to get the development tools like editor support to the next level?