I haven't seen anybody stating "why" Firefox is a better alternative than that "C" app. Firefox is a lot more secure. No popups, ads, etc., which stops all the garbage from coming on when you click Chromecast to watch something from the Net. I'm surprised there is not a method for this as of yet in Firefox.
Would be nice to also support Miracast, which is actually an open standard from the WiFi alliance and was removed in Android v9 to force everyone onto google's standard