Some other examples of what you are talking about: In the regular expression benchmarks, some entries implement their own idiomatic regex parsers or link to the PCRE2 library, rather than use the regex library that comes with the language implementation: https://benchmarksgame-team.pages.debian.net/benchmarksgame/..., https://benchmarksgame-team.pages.debian.net/benchmarksgame/...

This is, arguably, totally fine, because these are still valid programs that run (and run quickly). BUT, it makes the benchmark programs poor choices to compare the verbosity of languages. So statements like "For a language famed for its terseness, Haskell it turns out, isn’t as terse as expected" can't be supported when comparing benchmark programs that were written to maximize speed, rather than written to minimize developer time.

Fortunately, the Benchmark Game does publish all of its programs, including the ones that don't "win" the speed race, and it's possible to find nice, concise, idiomatic Haskell programs in there.