Sometimes it is about code quality. Defensively written, well-documented and well-tested code would not be as likely to suffer from such bugs.

It's not just subtle floating-point errors either, but also outright wrong maths that appears to work (see [1] for an example), memory leaks [2], buffer overflows [3] etc.

[1] https://www.youtube.com/watch?v=4gNYTqn3qRc

[2] https://news.ycombinator.com/item?id=20410166

[3] https://arstechnica.com/gaming/2021/03/how-to-beat-paper-mar...