Why aren't series / films dubbed in Serbian or something on Netflix?

Or Mexican

In Serbia or Spain, they are also synchronized in their language. In DE they are dubbed in German

Because here in Germany you only have the choice between the original sound (unfortunately not always) and German. If you go to Mexio, you have the series that are offered there also in Mexican

The films I wanted to watch, however, were not in German. Korean, Portuguese, or other savings only.