It’s just that smoothly is table stakes. Amazon raised the bar so now you have to do it smoothly blazing fast.
Amazon raised the bar. And then they completely failed to meet their own new higher bar.
Amazon will no longer allow you to select the speed of your shipping. Amazon will offer you shipping at whatever speed they feel is appropriate, and if you want faster shipping than that, you can suck it. This is a huge downgrade from the system Prime started out with.
And when Amazon fails to meet the shipping deadline they quoted you, again, you can suck it. This is not infrequent. This despite the fact that the deadline is something they made up.
Between this and Amazon's giving up on offering lower prices than other stores, I tend to prefer ordering from other stores.