I think the problem there is that the uncertainty bounds can be massive. Almost every task will have the form: "This task should take a day. But if the feature

I think the problem there is that the uncertainty bounds can be massive. Almost every task will have the form: "This task should take a day. But if the feature of the framework I plan to use turns out to be buggy, it might take a month. A bug is unlikely but not impossible, I handwave a guess at 10%." This sort of estimate might be reasonable, or not, depending how fractal you want to get with the backup plan of a month of tasks which themselves have wide uncertainty estimates. But it's also quite useless for planning. You end up with a Gantt chart that says "this project might take 3 months, or 5 years", which helps nobody. Hence #NoEstimates