Comment by Sephr

There's an obvious incentive they haven't tried: guaranteeing a lower app store margin like 1-2% instead of the 30% cut that Microsoft currently takes.

Google and Apple have already convinced a sufficient number of users users that their app stores are essential, so they can continue to charge whatever they like.

Microsoft didn't have the same luxury, so they needed to change this. They never made the change and it's too late now, but I think if they did this a few years ago they would be in a better position.