At best it led to a stakeholder demo where some business people would look at a form or something, ask some minor questions, then a new cycle would begin (with its context switching, planning stress and perverse JIRA games - all the negatives of Scrum).

I don't think many companies use such regular user feedback in their development process.

Perhaps it's that they don't need to? I actually think a lot of company dysfunction happens when the "official" system purports one set of goals (user feedback, regular pivots) but the "real" system purports others (executive driven initiatives, long sales cycles)