Because you iterate to validate.
Iterative approach to solving problems makes feedback from the people you’re designing for a central part of how a solution evolves.
You iterate because you know that you won’t get it right the first time. Or even the second.
Itrations allows you to test your hypothesis and ideas early so that you don’t invest in a single idea that in the end may not be the right one.
People are not adopting what you created.
Your solutions are always average because you never find resources to refine them later.
Although you wanted progress quickly, you are losing tons of time by patching never ending list of issues of your implemented solution.
You gain validation along the way which makes you confident that you are working towards better solution.
You have more ideas because you constantly learn from people you’re designing for.
You arrive quickly at successful solutions because you continually iterate, refine, and improve your work.