Yep. The advantage of Prime Now/Fresh is that if you put it in your cart, it's yours.
With Whole Foods online, your personal shopper is competing with in-store customers.
On a slightly related note, I've given up on Walmart for groceries. At the beginning of the pandemic, it was among the best. Now it's terrible. My last order, almost 80% of the items I wanted were either suddenly unavailable and removed from my cart at checkout, not available for delivery, or not delivered at all because they ran out just before delivery.
Two times before that, Walmart just forgot my order and left it behind. The first time it happened, my 6pm delivery was delivered at 8am the next morning, once customer service could get in touch with someone in the store. The second time, someone must have noticed it sitting there, because my 5pm delivery got delivered at 1am!