Here’s a wonderful post by Eric Higgins all about refactoring and technical debt. He compares giant refactoring projects to being similar to Tetris:
Similar to running a business, Tetris gets harder the longer you play. Pieces move faster and it becomes harder to keep up.
Similar to running a business, you can never win Tetris. There is no true finish line. You only control how quickly you lose.
Similar to running a business, allowing too many gaps to build up in Tetris will cause you to lose.
I love this comparison, despite my mediocre Tetris skills. It does feel like even "easy" development becomes harder as technical debt grows on a project, much the same way Tetris pieces gain speed and provide little time to react as the stack grows. However, I do think perhaps I have a more optimistic view of technical debt overall. If you work slowly and carefully then you can build up a culture of refactoring and gather momentum over time.