Earlier quoted context omitted.
Just have the application start the browser like daemons used to 20 years ago. Nowadays they can even send the PWA manifest to hide the browser appearance.
Are we really arguing why someone might want to have a "native" app instead of a browser window? There's many reasons why someone might want to have that.
I wasn't impressed with MSHTML when it came up as Active Desktop, nor I am impressed with anything that followed suit.