Good design does not accumulate technical debt.

Time spent on design is paid once. Repair work is paid on top of the design — and the end user pays for it one way or another: in the price, in ads, or even by the product being discontinued.

That is why design starts with the real-life process, not the interface: how the thing actually happens, including the times it goes differently. The goal is a product that takes the friction out of everyday life.