Large customers normally have lots of leverage: "if you don't give me a good deal, I will take my business elsewhere". I run an alternative to the Apple App Store for jailbroken iOS devices (Cydia); and, when I have sold software (which I did "at scale" for a decade) I absolutely was forced to cut deals--sometimes ones extremely lucrative for the developer--to keep the business of my largest clients from not only listing their products (which notably were generally ineligible, for technical reasons as opposed to content ones, from being available in the official App Store) with competing stores or even merely accepting payments themselves, but actively building their own competing stores! Think about it: if you are paying a hefty percentage of your revenue to someone else in fees--and are doing enough volume (as you are a large customer)--you can afford to hire an entire team to work on this problem as the App Store is in no way "magic" or anything... at which point you "may as well" offer the service to others in an attempt to cut the margins of your prior fee recipient. It should be the small customers who generally tolerate the (on a percentage basis) higher fees, as they are willing to pay a potentially "hefty cut" for the privilege of using an off-the-shelf, integrated solution that users trust, as the absolute cost of that larger cut is small, and is thereby unlikely to be large enough to make sense expending a bunch of effort building (and marketing) a bespoke solution (that users might not trust anyway); but if you aren't having to fight for the larger customers, something distorted is happening: that Apple and Google (both, which might be surprising to some but maybe less if you read Epic's lessor-known lawsuit against Google surrounding anticompetitive moves Google has taken--and maybe are now attempting to address, but only now--to lock in their Play Store) feel able to specifically squeeze their largest customers with seemingly no ramification is a testament to the power they possess to control and direct the relevant markets from their respective positions.