There is not any good design that was created without iteration.

Onur Cobanli ཡིས་འགྲེལ་བཤད་བརྗོད་པ།
In general, the design process is about improving things, making products better, and services superior. Testing product variants or service differences, i.e. iterating, is very important for making better designs; you test variants, you try new things, keep good and discard bad; iteration is the soul of design process; it is optimization and it is essential, obviously if you do not iterate, you settle for mediocre; regardless of how great your design is, if you iterate, you may potentially arrive at even greater designs.