MediaWiki has inherent bias toward English in the use of English namespaces in non-English wikis. It does not support non-English naming in English wikis.
If I am on a non-English wiki and use the following syntax to insert media, it works as expected.
If I am on an English wiki and use the following syntax to insert media, it does not work. It gives a redlink.
MediaWiki should be agnostic on what namespaces it accepts. [[Bild:image.jpg]] should resolve an image just as [[File:image.jpg]] would.
This furthers the mission of knowledge equity, particularly around knowledge creation. Changing the behavior of Mediawiki would help non-English language communities to reduce their reliance on English wikitext bits.
Perhaps there should be a setting to limit what languages are acceptable. For argument: If for some reason a Welsh wiki didn't want to use the English "File:" namespace they could discourage it's use by defining a restriction for English (and/or other languages).