Software projects are often of the type that are never finished (though there are counterexamples). You can finish milestones, but the content of milestones is

Software projects are often of the type that are never finished (though there are counterexamples). You can finish milestones, but the content of milestones is rubbery. You can often just declare them done by shuffling planned content into the next milestone. A software project is not finished before reaching its minimal viable functionality and first release. After that, all further changes are just small projects on top of that project. A big enough project can become its ow source of procrastination: you can avoid working on something difficult, in that project, by working on something easy instead, in that same project. You're still working on the project, so all is good!