A few more data points: this does work for iOS 14+ build targets in Xcode 13 13A233 (using swift 5.5). It also used to work on macOS build targets using Xcode 13 betas. It stopped working in Xcode 13 RC (13A233) for macOS build targets only.
My assumption was that they temporarily pulled support for it on macOS build targets as of the Xcode 13 release candidate and until Monterey was released. And now Monterey is released and it appears the problem remains for macOS targets only.