Hey @tjeffrey!
I believe the ability to add all of the questions to a questions bank at the same time can be done by exporting the New Quiz as a QTI file, and then importing the QTI file to an Item Bank. Check out the following Community Guides to show how this is done.
How do I export a New Quiz from a course?
How do I import questions from a QTI package into an item bank in New Quizzes?
Realize that once you import the QTI file into the Item Bank, the questions in the Item Bank will not be associated with the original quiz. If the plan is to use the Item Bank with a quiz, you may want to create another quiz and use the Item Bank to add questions to the newly created quiz. Seems like a few extra steps, but it is easier and faster than adding each question one at a time.
Hope this helps!