People have asked for this or the Spanish version of Angular or Russian Java. If I only spoke those languages I might want that as well. Surprised no one has tried to introduce this into popular programming languages.

The times when this was decided are remote in terms of computing. We're probably talking about mid-eighties. Excel is an office tool, and probably most of its users work in offices where not a single word of English is spoken, ever. So I don't think it was "asked by the users" but rather what's expected from a basic office tool, to be localised in your language.