Comment by skydhash

Most projects don’t change that much either. Head over to a big open source project, and more often you will only see tweaks. To be able to do the tweaks require a very good understanding of the whole project (Naur’s theory of programming).

Also in software, we can do big refactors. F1 teams are restricted to the version they’ve put in the first race. But we do have a lot of projects that were designed well enough that they’ve never changed the initial version, just build on top of it.