Prime Now is now unavailable entirely. At checkout, it simply says "No delivery times available" for all stores.
Amazon Fresh also gives no available delivery windows.
They're definitely struggling for the same reason grocery stores are; it's not a stock limitation, it's not enough hands to move it.
Got an email from a company i do work with, and they’re calling for 21 day delays for shipping items, and suspending new orders. Just because they literally cannot package and ship fast enough.