The above code will output thorn which is more correct than Y.

This extension allows you to transliterate text in non-latin characters (such as Chinese, Cyrillic, Greek etc) to latin characters. Besides the
transliteration the extension also contains filters to upper- and lowercase latin, cyrillic and greek, and perform special forms of transliteration such as converting ligatures such as the Norwegian “æ” to “ae” and normalizing punctuation and spacing.

It’s not about sanitizing, it’s about creating search engine/user friendly ascii urls that are as close as possible to the original title but excludes national characters to be a little bit more international viable.

And to clarify, the above code example is shortened. For the sake of an example it is not necessary to include all western characters that needs to be supported.

One could argue that it’s not really worthwhile to write a sanitizer for non-alphabetic and numeric characters as no-one tends to use them in their titles anyhow.. If you do write it up, I imagine there’s a few more characters that need replacing.