I can only see this going into a very dystopian path. Based on their actions, I don't trust these companies, their security practices, nor their privacy policies. Why would I give them my biometrics? And my full palm, at that!? Hell no!
I don't understand what this solves... We can use a card faster than this (a mere tap), and if we forget our card, it's programmed into our phones and even our watches as a backup.
Its meant to save you a step. Before at whole foods you had to get out your phone, open the amazon app, scan your prime QR code, then get a card and pay. This just does all that with an enrolled palm.
I still don't trust it. I laughed at it when I saw it and even the clerk admitted it was dumb.