Setup Assistant refers to two separate tools that help you set up features in Google Analytics.
The GA4 Setup Assistant wizard in a Universal Analytics 4 property helps you migrate from a Universal Analytics property to a Google Analytics 4 property. It adds a Google Analytics 4 property to your Analytics account that collects data alongside your Universal Analytics property. Learn more
The Setup Assistant tool in a Google Analytics 4 property helps you finish setting up your Google Analytics 4 property. Learn more