"MySQL was also potentially faster as it did not implement all features of the SQL standard. "
This is a not great start. I assume it refers to MyISAM which has not been relevant for over a decade at this point. InnoDB made different design than PG decisions and was (and perhaps still is) faster at point lookups.
https://github.com/seanwevans/pg_gpt2
https://github.com/seanwevans/pg_shell
https://github.com/seanwevans/pg_os
This is a not great start. I assume it refers to MyISAM which has not been relevant for over a decade at this point. InnoDB made different design than PG decisions and was (and perhaps still is) faster at point lookups.