Aside from increasing MySQL performance, it also makes the server more resilient and easier to extend with plugins. The fruits of the ongoing top-down reworking of the SQL parser are seen in 8.0 ...

We started development with the MySQL 4.1.1 release and noticed a few complex queries where the ordering did not work as expected; we were forced to rewrite the queries or break a single query ...

It seems that MySQL 4.1 isn't mature enough to handle the complexities of UTF-8. It would seem to me (having used Oracle) that specifying UTF-8 as the database encoding would take care everything.