That article is old. DynamoDB was used because of the old, weak consistency model of S3. Writes were atomic, but lists could return old results so needed consistent list of objects.
But in 2020, S3 changed to strong consistency model. There is no need to use DynamoDB now.
The problem was not the eventual consistency model, was the speed of the object list.
"...Finding objects based on other attributes, however, requires doing a linear search using the LIST operation. Because each listing can return at most 1000 keys, it may require many requests before finding the object. Because of these additional requests, implementing attribute-based queries in S3 alone can be challenging..."
Here is the architecture of Amazon Drive and the storage of metadata.
"AWS re:Invent 2014 | (ARC309) Building and Scaling Amazon Cloud Drive to Millions of Users" - https://youtu.be/R2pKtmhyNoA
And you can see the use here at correct time: https://youtu.be/R2pKtmhyNoA?t=546