FWIW, if you distribute your app as an installable PWA, the google guidelines are clear for reducing install friction on Windows/Chrome/Mac/Android and Let's Encrypt is your cert generator. Perhaps platform vendors treat binaries malicious by default because it so often leads to privilege escalation. Build an app in the web context and you have a cross platform sandbox with a standardized permission model. Alas, this is not very helpful advice for folks who haven't grown up developing for the web.