Cleaning up is boring but also creates a shocking amount of leverage.

It's magic.

A ton of value created, with no single concrete thing unlocking that much.

When the software now does what it wants to do, but more robustly, that's tons of prediction errors avoided for users and also other engineers.

Cleaning up is part of the Second 90%.

It doesn't require grand engineering plans.

It just is a matter of people pitching in, good tooling, good judgment, etc.