It doesn't seem like a big deal, but this is just so much more annoying than using my palm that not only links my payment method but also prime membership.
Now I need to tap through a stupid app and scan a code.
We always stopped at whole foods on the way home from the gym, and I didn't always have my phone with me or readily accessible. This will definitely cause me to cut back on this quick stop in / impulse purchases.
If you have an iOS phone you can create a shortcut on your home screen that jumps directly to the code in the Amazon app. Whole Foods app may have the Shortcuts integration too, but I use the Amazon app.
The code both applies your Prime membership and links your preferred payment method.