Valve is an excellent example of a company that is privately owned, so they don’t have to satisfy shareholders with constant growth for growth’s sake. And yet they’re still growing and making a profit, because they make a good product.
Phil and Xbox don’t have that luxury because their masters sold out decades ago.
They could definitely treat developers better, but they’re an example of treating customers right. That’s why they’re the biggest platform, and that’s why they admittedly have something debatably close to a monopoly.