> I kind of doubt this, but have no numbers to back me up. Do you have any numbers or actual facts to support that statement?
I don't have a measure of it but Google and Facebook did - and they found that estimation is BS and never achieved. They never institute scrum/kanban/agile nonsense as a result.
Without data, the constant and persistent failure to estimate projects - over 40 years - should be good enough data.
On my main project at work we hit exactly 100% estimation of tasks in February this year. In March we were like 110%.
Estimation of tasks and projects are two completely different things.