> In a good “ideal” org the only source of requirements should be users, aka customers, aka real people, user facing products, teams etc.

There are many other source of requirements that matter a lot. One heavily underestimated one is employee frustration. A frustrated employee is less productive and is at risk of leaving the org which incurs huge costs.

A few other ones: environmental impact, social impact, security, ethics, data safety/privacy, regulamentory compliance.

You might say that all these eventually end up as a requirement from users, for example "an employee leaving because he is frustrated means it takes longer to deliver features to a customer". But that is a very roundabout way of looking at it.