That's not what the article showed. It showed that synchronous IO latency was the limiting factor. By arranging your IOs into little 512-byte chunks, you don't

That's not what the article showed. It showed that synchronous IO latency was the limiting factor. By arranging your IOs into little 512-byte chunks, you don't make it terribly easy for the filesystem to efficiently use the underlying device --not surprising, given that it doesn't even want to work in 512 byte sectors, and operates more efficiently with lots of a parallel io operations.