Apple should commit to a support life cycle on the front end then. You are being sold this product with support for a minimum of 'x' time frame. You are not 'buying' this.

Ideally what Stop Killing Games would like is game preservation, but at minimum we need honesty/transparency about product market places. I finally know what my minimum OS lifecycle is for my Pixel phone, and I can make a comfortable purchase decision based on that.

Even Steam isn't immune to this, it simply has an good track record relative compared to most other platforms.

Apple took a ~30% cut of the sale of the product. That should calculate into it's servicing of the product. To Ross Scott's points (and many others), if you have a perpetual service but a onetime/lifetime payment, the business model will eventually not net out.