If there are only two sellers of mobile apps, you can't just "give your money to someone else" because no one else exists. That's the essence of antitrust, whether it be monopoly, duopoly, or oligopoly. I'd agree with you if there were a free market of device OSes and app stores, but a market of only two is fundamentally unfree.
If there are two, there is someone else, basic English grammar rules here.
Then there are feature phones like those Nokias with KaiOS, Jolla, Tizen,... be the change you want the world to become, instead of giving the money and then feeling entitled to something it wasn't available right from the start.