For the same reason all streaming services and game storefronts don't provide a generalized API to be used with 3rd party front ends. They all want to pretend t

For the same reason all streaming services and game storefronts don't provide a generalized API to be used with 3rd party front ends. They all want to pretend that they are the only service you'll ever need/use, and their UX isn't designed for practicality, it's designed for marketing.