As you mention two companies I can only assume the other is Google and android. Which I find odd as I have multiple other appstores and repositories on my phone and every other android device I have owned. My phones and tablets usually come with not just the Google Play Store, but also the manufacturers app store, and I install fdroid on all my android devices, and have in the past installed the Amazon app store on my phones back when Amazon and Google were having a spat over audible book sales and you breifly couldn't buy books on the Google hosted version of audible. So I don't see the problem. There are many third party app stores on the android half of the marker if you as a developer dont like the terms for using Google Play, then list you app on another storefront with more agreeable terms or your own webpage.