To train for business and user outcomes LLMs need what they currently don't have: open insights into the real world app and business metrics.

If you meant training on UI and features of established apps then it gets even more complex, as success of B2C apps is obscured by their pricing strategies and marketing, and business models for successful B2B apps like Jira/Confluence/Office often revolve around sales, partnerships and other non-product things like that.

Any business is a set of design decision someone made, with their app just being a small subset of these.