As things currently are you are better off with C++ on the server than with Swift. This is how bad things in reality are.
I could imagine a micro-service here or there where Swift is involved in some kind of bigger enterprise architecture, or as a hobby project, but the ecosystem, the libraries, the documentation, and the community just aren’t there yet.
It’s pretty easy to take Apple’s HTTP implementation, add a router, integrate a template engine and have something running, but I don’t see a reason for this in a professional environment, and I still don’t see Apple as the company who will push a technology that isn’t directly bound to their hardware.
And Swift 6 will likely see Swift on Windows, sometime next year. That work will be built upon the efforts for Swift on Linux, so you can get ready for that today.
