Another interesting article from Feb-2024 [0] where the cost of inserting a uuid7() and a bigint is basically the same. To me it wasn't quite clear what the problem with the buffer cache is but the author makes it much more clear than OP's article:

> We need to read blocks from the disk when they are not in the PostgreSQL buffer cache. Conveniently, PostgreSQL makes it very easy to inspect the contents of the buffer cache. This is where the big difference between uuidv4 and uuidv7 becomes clear. Because of the lack of data locality in uuidv4 data, the primary key index is consuming a huge amount of the buffer cache in order to support new data being inserted – and this cache space is no longer available for other indexes and tables, and this significantly slows down the entire workload.

0 - https://ardentperf.com/2024/02/03/uuid-benchmark-war