[cestith]

In software it's basically free if you want exactly the same building. Bits are cheap. Even physical media to store the bits is cheap.

Sure, the bricks, mortar, framing lumber, concrete, drywall, conduit and such for a building cost a fair amount of money. Then there's the labor to actually put it together. But one of the big costs is the architecture and (literal) groundwork.

The fixed costs of a building are fairly steep, but miniscule compared to redesigning it over and over. In software we generally get away with much cheaper fixed costs of deployment but redesign is still redesign.

We're typically happy to spend some time redesigning and paying that cost because we're not actually demolishing and rebuilding parts of the project with high deployment costs like renovating an existing building. Throwing away the old copy and deploying a new one is essentially free. So we shift the budget to more redesign. There should be a limit on how often, though, if we ever want to move on to different problems.