Thank you for the question.
I would say that it's neither one nor the other.
In agile procurement, a competitive process is used to select one supplier. In most cases, several suppliers are used. The goal is to divide a large project into several small parts. In fact, a number of suppliers can be selected to participate in the project. The idea is to have an opportunity to revise the project to adjust the objectives and the deadline, for example.
Rather than have one big project, one big contract or one big competition, you're dividing it into pieces, and in fact often working with multiple vendors, but also getting feedback partway through, revisiting and adjusting the schedule and the approach going forward.