FWIW you don't really need an app store, you could download APKs off vendors/publishers, verify signatures and mind updates (except Apple won't let you, but that's a different story).
You want to use an app store, fine, use an app store and pay some commission on what you buy there, it's not a problem, reaching into any purchase done after the initial download is.
You want to use an app store, fine, use an app store and pay some commission on what you buy there, it's not a problem, reaching into any purchase done after the initial download is.