I agree with everything you wrote, except as a designer I wanted to point out that the lack of scope limitation is not usually due to design, but rather product and marketing who drive new features, because their job is to increase new customers, and improving life for existing customers is a far second – only so far as potential new customers may be impacted (reviews, comparisons with competitors, or churn). So long as they can mostly keep existing customers they will always fight against spending development time on improving their experience, when they could add a new point to the feature list for marketing.

The issue is the drive for infinite growth is counter to a human-usable quality-focused UX (with a focused scope and focused target audience).