Someone downvoted the question. It's legitimate and frustrating to be forced to use the Microsoft store. Don't downvote just because the question tone expresses deep frustration at a Microsoft decision that forces an unwieldy deployment approach, especially for corporates where the store is effectively banned.

However, there is a solution for Blazor apps that doesn't require the store and is cross platform for MacOS , Linux and Windows:

• Photino. This appears to existing browsers on a machine rather than embedding a new browser copy as Maui does. The only dependency on Windows is for the WebView2 Runtime on Windows. On MacOS there's no dependency, and Linux has a similar solution to Windows.
  Photino Blazor : https://github.com/tryphotino/photino.Blazor/tree/master

Alternatively, if someone can tell me how I can build an EXE or MSI from my existing Maui app I'll happily (very happily) accept that as an answer.