> In the vast majority of cases, these are not your customers. These are apple's customers they have given you access to.
This is problematic argument, that imo we should not accept in _any_ commercial context.
* Are people browsing the web on an iPhone Apple's customers, and therefore 30% of web sales should be collected too?
* If you use Comcast to access the internet, are you Comcast's customer? They're giving the retailer access to your traffic, so they should take a cut of every online purchase?
* Should your headphones take a cut of all music streaming revenue, and refuse to play non-compliant music?
* Should your TV take a cut from every video stream provider they allow to show video to their customers?
There is significant value to society in general-purpose devices & services, where the user pays for something concrete, and can then use it with any 3rd party provider in any way they like.
That principle has been a key driver of digital innovation for decades, and allowing it to disappear would be a Very Bad Thing.