The issue is now - the use of Swift outside of the Apple ecosystem is remarkably stifled, given the lack of Apple support.
A language truly acquires mainstream mindshare and community, only if it can extend its use beyond Apple's OSes.
It’s an open source project that’s more and more detached from Apple itself every release, with lots of contributors making it better and better on Android and windows all the time.
It is possible to get a vscode ide environment working for cross platform development and debugging today, which was not that easy or possible even a few years ago.
There is at least one pretty sizable software project that has shipped a product on Android and windows using swift.
I think swift 6 is going to be great for cross platform uses, but convincing folks to try it still won’t be easy.