Debug earlier than later
The earlier you can investigate and fix a bug, the better. It’s easier, faster, and cheaper.
Earlier in development means less code to check. Less complexity to navigate.
Earlier in deployment means you have more debug facilities and tools available. Less or no damage to repair or clean up.
Earlier in time means they interfere with feature development less. Workarounds and bad habits don’t develop.
Keeping bug counts low pays off.