While I acknowledge that David has an extremely good first-hand knowledge about Moodle plugins (being the plugins master wizard), many Moodle users world-wide are restricted to using CORE Moodle for teaching, as additional plugins are often not available (eg, free Moodle cloud), or expensive to add (eg, Moodle Partners) by many hosting sites. And the language (other than English) support Moodle has had since version 1 is excellent, but there is still room for improvement.
According to the Statistics page at https://moodle.net/stats/ , the number of Moodle non-English sites might even be larger than the number of English Moodle sites.
So, I think Moodle would be even better if it had a stronger and easier support for many languages, preferibly simultaneous, usage.