But how often would you actually have to rewrite an entire 10-20k LOC project at once?
As you need to add functionality, you can opportunistically find ways to improve the codebase toward a better/more maintainable structure.
I have several large codebases I work on which probably get totally rewritten every 18 months or 2 years, however incrementally.
If you have a working project and you think you need to throw it all out and start from scratch probably it's worth a second thought.
We always talk about time when the elephant in the room is energy. People say we don’t have “time” for that and someone else gets out a calendar and tries to disprove them. Followed by a bunch of backpedaling with other excuses and followed up with foot dragging.
The second elephant in the room is job security. People who write baroque code are hard to fire. Nobody wants to invest energy in understanding their private little Bedlam.
Maybe some people have very small projects compared to what I work on? Or maybe they are talking about the design of a single small component?
I inherited a codebase that needed some refactoring because it was written “to just get it shipped”. If completely fell apart with more users and has taken me a year to get it where it needs to be.