I think the author is specifically evaluating low-concurrency in-memory workloads here. The previous post describes why regressions for those workloads might be "not a surprise": https://smalldatum.blogspot.com/2017/05/the-history-of-low-c...
Those blindly suggesting MariaDB or Percona is all well and good but naive. Percona generally follows MySQL upstream but makes their own little tweaks which could be (but are not always) fixed in MySQL upstream based on differing specific priorities.
MariaDB is highly diverged at this point and likely has a whole different set of problems and benefits.
Author of these posts is well known for a long (10+ years) history of working with MySQL at a deep level rivalling that of many of the developers, generally writes good stuff (though is not infallible :)
Even their own benchmarks show MySQL 5.7 dipping below previous versions at the low end of the concurrency scale.
I also showed the impact for IO-bound workloads, and even there the regression is larger than I want. But not as bad as the in-memory workloads.