The keyword here is "should" :) Back then DynamoDB also had a problem with scaling the data can be easily split into partitions, but it's never merged back into fewer partitions.
So if you scaled up and then down, you might have ended with a lot of partitions that got only a few IOPS quota each. It's better now with burst IOPS, but it still is a problem sometimes.
So if you scaled up and then down, you might have ended with a lot of partitions that got only a few IOPS quota each. It's better now with burst IOPS, but it still is a problem sometimes.