From the trenches, the observable reason that approaches like this aren't taken up is often because of the power dynamics at play. Stakeholders want to treat d

From the trenches, the observable reason that approaches like this aren't taken up is often because of the power dynamics at play. Stakeholders want to treat delivery teams as feature factories, and typically have the organisational power to reject estimates that aren't in the form of "this will be done tomorrow/next week/in three months". They choose to reinforce the viewpoint that an inability to provide and keep to hard delivery deadlines is a marker of incompetence, rather than a realistic assessment of the basic physics of the situation. This is - to put it mildly - not helped by situations where hard deadlines are agreed to without speaking to delivery teams at all. There is a lack of maturity in how software delivery is commissioned in the industry, but the fundamental issue is that the political drivers that result where Taylorist management interfaces with unpredictability in delivery reward behaving in a way that doesn't improve that maturity.