I am not sure if you are intentionally or not missing the point. The general idea is that the Epic App Store will have dramatically less people in it. If you move your app to a different store with less people using it you make less revenue. Getting a larger chunk of a much smaller revenue number is worse than getting a smaller chunk of a much larger revenue number. The same principle is why businesses go get funding to build their business. They give up an ownership percentage, but in doing so make multiples more money because of the same principal.And this is only in the EU? Or are you comparing World wide distribution compared to EU. Plus your 0.1%. Where did that come from? Based on your logic, I should have 100,000 apps on my phone.
Also, the number of apps on your phone has nothing to do with this. In my pretend scenario, with pretend numbers, you can decide for yourself how many apps people on average install. If you want to use a number where you end up with 100,000 apps on your phone, great. But you could also pick a different more reasonable number.