Why people aren't building sites that work with everything and using the app merely to authenticate? That will allow you to capitalize via the *stores but not b

Why people aren't building sites that work with everything and using the app merely to authenticate? That will allow you to capitalize via the *stores but not be hostage to it. Some clueless people now will try to educate me that a native client is better, even it not having bookmarks, several tabs, browser extensions, pitch to zoom on every page, etc etc