The benefits of doing the work correctly the first time are immense. In business, it can reduce costs, as you minimise the input material used, or time taken to produce a product or to deliver the service. In personal life, it can also save time, costs, and reduce stress, as we can finish and move on to the next exiting task or project.
I understand, you might say, but what if the work is novel? How then should we approach it. I agree that, in truly novel cases, iterations may be required to get to your best work. Even with novelty, there is an argument for using a defined process, i.e., while all projects are different, the project delivery process has similar phases which you can optimise.
Doing our best work the first time, however, requires us to prepare. To know as much as we can before we start, and to learn as we go. When we slow down to first determine what needs to be done, by whom, and in which sequence, we help ensure that our work is done as fast as possible, while also improving the odds of meeting the quality standards of our client. Whether that client is us or an external party, we can then rejoice in the knowledge that we did our best, in time.