The benchmark with 1B rows in this blogpost seems irrelevant for comparing performance of different programming languages.
It seems like the execution time of a program would be dominated by loading data from the file. And a lot of people posted solution with specs of cpu but not specs of disk (hdd, ssd, raid) although that seems more relevant.
Why would they compare languages and solutions in this way?
To answer your question about environmental factors - from the repo:
That seems to only be for the Java code
The show and tell page is exactly that, show and tell; not a scientific or balanced comparison.
The original challenge only compared JDK solution in this way. Further down there is a link to another repo that does that same across many languages, and uses the same M1 MacBook Pro to run the tests.